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Shape polarization in the tin isotopes near N = 60 from precision g-factor measurements on short-lived 11/2− isomers. Gray, T.J.; Stuchbery, A.E.; Dobaczewski, J.; Blazhev, A.; Alshammari, H.A.; Bignell, L.J.; Bonnard, J.; Coombes, B.J.; Dowie, J.T.H.; Gerathy, M.S.M.; Kibédi, T.; Lane, G.J.; McCormick, B.P.; Mitchell, A.J.; Nicholls, C.; Pope, J.G.; Reinhard, P.-G.; Spinks, N.J.; Zhong, Y. in Physics Letters B (2023). 847 138268.
The g factors of 11/2− isomers in semimagic 109Sn and 111Sn (isomeric lifetimes τ=2.9(3) ns and τ=14.4(7) ns, respectively) were measured by an extension of the Time Differential Perturbed Angular Distribution technique, which uses LaBr3 detectors and the hyperfine fields of a gadolinium host to achieve precise measurements in a new regime of short-lived isomers. The results, g(11/2−;109Sn)=−0.186(8) and g(11/2−;111Sn)=−0.214(4), are significantly lower in magnitude than those of the 11/2− isomers in the heavier isotopes and depart from the value expected for a near pure neutron h11/2 configuration. Broken-symmetry density functional theory calculations applied to the sequence of 11/2− states reproduce the magnitude and location of this deviation. The g(11/2−) values are affected by shape core polarization; the odd 0h11/2 neutron couples to Jπ=2+,4+,6+... configurations in the weakly-deformed effective core, causing a decrease in the g-factor magnitudes.
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Beta-delayed neutron spectroscopy of 133In. Xu, Z. Y.; Madurga, M.; Grzywacz, R.; King, T. T.; Algora, A.; Andreyev, A. N.; Benito, J.; Berry, T.; Borge, M. J. G.; Costache, C.; De Witte, H.; Fijalkowska, A.; Fraile, L. M.; Fynbo, H. O. U.; Gottardo, A.; Halverson, C.; Harkness-Brennan, L. J.; Heideman, J.; Huyse, M.; Illana, A.; Janiak, \L{}.; Judson, D. S.; Korgul, A.; Kurtukian-Nieto, T.; Lazarus, I.; Licifmmode \u{a}else \u{a}\fi{}, R.; Lozeva, R.; Marginean, N.; Marginean, R.; Mazzocchi, C.; Mihai, C.; Mihai, R. E.; Morales, A. I.; Page, R. D.; Pakarinen, J.; Piersa-Si\l{}kowska, M.; Podolyák, Zs.; Sarriguren, P.; Singh, M.; Sotty, Ch.; Stepaniuk, M.; Tengblad, O.; Turturica, A.; Van Duppen, P.; Vedia, V.; Vi nals, S.; Warr, N.; Yokoyama, R.; Yuan, C. X. in Phys. Rev. C (2023). 108(1) 014314.
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Prompt gamma rays from fast neutron induced reactions on cerium and chlorine. Ophoven, Niklas; Ilic, Zeljko; Mauerhofer, Eric; Randriamalala, Tsitohaina H.; Vezhlev, Egor; Stieghorst, Christian; Révay, Zsolt; Brückel, Thomas; Jolie, Jan; Strub, Erik in Journal of Radioanalytical and Nuclear Chemistry 232 (2023) 3133 (2023). 332(8) 3133--3145.
Prompt gamma rays of cerium and chlorine were investigated with the FaNGaS (Fast Neutron-induced Gamma-ray Spectrometry) instrument operated at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching. The gamma radiation was emitted from (n,n'), (n,p) and (n,α) reactions induced by the irradiation of a cerium(III) chloride (CeCl3) sample with a beam of fission neutrons. Additionally, a polyvinylchloride (PVC, (C2H3Cl)n) sample was irradiated to verify possible interferences between gamma lines of cerium and chlorine. We identified 87 prompt gamma lines of cerium and chlorine. From these, we assigned 58 lines to the (n,n') reaction in cerium (one for 136Ce, 41 for 140Ce and 16 for 142Ce), 23 to the (n,n') reaction in chlorine (15 for 35Cl and 8 for 37Cl), 5 lines to the 35Cl(n,p)35S reaction and 1 line to the 35Cl(n,α)32P reaction. We present relative intensities and fast-neutron spectrum-averaged partial cross sections of the aforementioned gamma lines and compare them with available literature data. Identification of new lines and discussion of possible errors adds important value to the literature data found to be consistent with our results. In addition, for a counting time of 12 h we estimate the detection limits for cerium and chlorine as 1 and 2 mg, respectively.
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Evidence of nonstatistical neutron emission following beta decay near doubly magic 132Sn. Heideman, J.; Grzywacz, R.; Xu, Z. Y.; Madurga, M.; Escher, J. E.; Kawano, T.; Algora, A.; Andreyev, A. N.; Benito, J.; Berry, T.; Borge, M. J. G.; Costache, C.; De Witte, H.; Fijalkowska, A.; Fraile, L. M.; Fynbo, H. O. U.; Gottardo, A.; Halverson, C.; Harkness-Brennan, L. J.; Illana, A.; Janiak, Ł.; Judson, D. S.; King, T. T.; Korgul, A.; Kurtukian-Nieto, T.; Lazarus, I.; Lica, R.; Lozeva, R.; Marginean, N.; Marginean, R.; Mazzocchi, C.; Mihai, C.; Mihai, R. E.; Morales, A. I.; Page, R. D.; Pakarinen, J.; Piersa-Siłkowska, M.; Podolyák, Zs.; Singh, M.; Sotty, C.; Stepaniuk, M.; Tengblad, O.; Turturica, A.; Van Duppen, P.; Vedia, V.; Vinals, S.; Warr, N.; Yokoyama, R.; Yuan, C. X. in Phys. Rev. C (2023). 108(2) 024311.
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Muonic atom spectroscopy with microgram target material. Adamczak, A.; Antognini, A.; Berger, N.; Cocolios, T. E.; Deokar, N.; Düllmann, Ch. E.; Eggenberger, A.; Eichler, R.; Heines, M.; Hess, H.; Indelicato, P.; Kirch, K.; Knecht, A.; Krauth, J. J.; Nuber, J.; Ouf, A.; Papa, A.; Pohl, R.; Rapisarda, E.; Reiter, P.; Ritjoho, N.; Roccia, S.; Seidlitz, M.; Severijns, N.; von Schoeler, K.; Skawran, A.; Vogiatzi, S. M.; Warr, N.; Wauters, F. in The European Physical Journal A (2023). 59(2)
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Updated analysis of the 170Er(p,t)168Er reaction data. Bucurescu, D.; Pascu, S.; Graw, G.; Hertenberger, R.; Wirth, H.-F.; Faestermann, T.; Krücken, R.; Mahgoub, M.; Jolie, J.; Brentano, P. von.; Heinze, S.; Möller, O.; Casten, R. F.; Meyer Brittingham, D. A. in Phys. Rev. C (2023). 108 014310.
More than 200 states up to 4.1 MeV excitation have been populated in 168Er with the 170Er(p,t) reaction at 25 MeV incident energy. About 80 of these states, with 0+ and 2+ assignments, were reported in a previous publication [D. Bucurescu et al., Phys. Rev. C 73, 064309 (2006)]. The present work considerably enriches the knowledge of this nucleus. A multistep coupled-channels analysis of the angular distributions is now presented for all the states observed in this experiment. Spin and parity values between 0+ and 7− are newly assigned for more than 100 states. For the states already reported in the ENSDF database with Jπ values there is a good agreement with our values. The 168Er nucleus remains one of the best experimentally known nuclei for states with low and medium spins below 4 MeV excitation energy, representing a challenge for future microscopic structure model calculations aiming to disentangle the contributions of different excitation degrees of freedom.
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X-ray-γ fast-timing lifetime measurement of the 6_1+ state in 206Po. Stoychev, K.; Djongolov, M.; Karayonchev, V.; Rainovski, G.; Ley, M.; Jolie, J.; Bittner, D.; Blazhev, A.; Dunkel, F.; Esmaylzadeh, A.; Fransen, C.; Garbe, J.; Gerhard, L. M.; Gerst, R.-B.; Geusen, K.; Gladnishki, K. A.; Häfner, G.; Kalaydjieva, D.; Klöckner, L.; Knafla, L.; Kocheva, D.; Kornwebel, L.; Müller-Gatermann, C.; Nikodem, E.; Régis, J.-M.; Schomacker, K.; Stoyanova, M. in Phys. Rev. C (2023). 108(1) 014316.
Low-lying states in 206Po were investigated using the fast-timing technique with LaBr3(Ce) and high-purity germanium detectors. The excited states in this nucleus were populated via two consecutive electron capture decays from 206Rn. The parent isotope was produced in the 194Pt(16O,4n)206Rn fusion-evaporation reaction at the FN-Tandem facility at the Institute for Nuclear Physics, University of Cologne. The previously known value for the lifetime of the 4_1+ state in 206Po was confirmed using the generalized centroid difference (GCD) method. The lifetime of the 6_1+ state was determined from β decay in the first application of the GCD method for x-ray–γ coincidences. A Monte Carlo based approach was applied to address the indirect population of the 6_1+ state by the decay of 206At. The experimental results were examined in the context of the transition of single-particle excitations to collective behavior in the neutron-deficient Po isotopes. The obtained B(E2;6_1+→4_1+) value suggests that for the 6_1+ states in even-even Po isotopes the transition from a noncollective regime at N=126 to a collective regime occurs at N≤120.
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Lifetime measurements in low yrast states and spectroscopic peculiarities in 182Os. Harter, A.; Esmaylzadeh, A.; Knafla, L.; Fransen, C.; Spee, F. v.; Jolie, J.; Ley, M.; Karayonchev, V.; Fischer, J.; Pfeil, A. in Phys. Rev. C (2023). 108(2) 024305.
Lifetimes of the low-lying yrast states 2+,4+, and 6+ of the unstable nucleus 182Os were measured using digital fast-timing techniques. The lifetimes of the 4+ and 6+ states were determined for the first time. The remeasured value for the lifetime of the 2_1+ state was taken into account to evaluate the discrepancy between two inconsistent literature values. The lifetimes and extracted B(E2) values are presented and discussed in terms of collective signatures and transitional phenomena. The B(E2;4_1+→2_1+)/B(E2;2_1+→0_1+) ratio of 1.39(7) supports the interpretation of 182Os as a rigid rotor. This value is discussed in the context of these of the neighboring isotopes and isotones and calculations in the framework of the interacting boson model 1. Additionally, competing influences from the near lying collective deformed region,γ-soft rotors, X(5) symmetry, and neighboring regions of shape coexistence in low excitation states are assumed to influence the structure of the nucleus of interest: The trend of the excitation energies of the γ- and Kπ=0–bands in the osmium isotopic chain change remarkably at 182Os. This consideration helps to us delimit and understand the structural transitions in the isotopic and isotonic chains that intersect at 182Os.
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Lifetime measurements in99Nb and 99Zr: Investigation of shape coexistence. Pfeil, A.; Nomura, K.; Gavrielov, N.; Régis, J.-M.; Köster, U.; Kim, Y. H.; Esmaylzadeh, A.; Harter, A.; Jolie, J.; Knafla, L.; Ley, M.; Karayonchev, V. in Phys. Rev. C (2023). 108(3) 034310.
The A≈100 mass region is of special interest due to a rapid shape transition, observed by going from neutron number 58 to 60, especially pronounced in the Zr isotopes, where 98Zr is weakly and 100Zr is strongly deformed. To further examine this intricate phenomenon, in this work lifetimes of low-lying excited states in the nuclei 99Zr and 99Nb were determined using fast-timing techniques and an experimental setup consisting of four LaBr3(Ce) detectors. Neutron rich A=99 fragments were produced in neutron induced fission and separated by the spectrometer LOHENGRIN at the Institut Laue-Langevin in Grenoble, France. Experimental values are compared to two different calculations in the framework of the interacting boson-fermion model and discussed in the context of shape coexistence.
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133In: A Rosetta Stone for Decays of r-Process Nuclei. Xu, Z. Y.; Madurga, M.; Grzywacz, R.; King, T. T.; Algora, A.; Andreyev, A. N.; Benito, J.; Berry, T.; Borge, M. J. G.; Costache, C.; De Witte, H.; Fijalkowska, A.; Fraile, L. M.; Fynbo, H. O. U.; Gottardo, A.; Halverson, C.; Harkness-Brennan, L. J.; Heideman, J.; Huyse, M.; Illana, A.; Janiak, \L{}.; Judson, D. S.; Korgul, A.; Kurtukian-Nieto, T.; Lazarus, I.; Licifmmode \u{a}else \u{a}\fi{}, R.; Lozeva, R.; Marginean, N.; Marginean, R.; Mazzocchi, C.; Mihai, C.; Mihai, R. E.; Morales, A. I.; Page, R. D.; Pakarinen, J.; Piersa-Si\l{}kowska, M.; Podolyák, Zs.; Sarriguren, P.; Singh, M.; Sotty, Ch.; Stepaniuk, M.; Tengblad, O.; Turturica, A.; Van Duppen, P.; Vedia, V.; Vi nals, S.; Warr, N.; Yokoyama, R.; Yuan, C. X. in Phys. Rev. Lett. (2023). 131(2) 022501.
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Improving fast-timing time-walk calibration standards: Lifetime measurement of the 2_1+ state in 152Gd. Knafla, L.; Harter, A.; Ley, M.; Esmaylzadeh, A.; Régis, J.-M.; Bittner, D.; Blazhev, A.; {von Spee}, F.; Jolie, J. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2023). 1052 168279.
A 152Eu source was measured for 28 days using an experimental setup consisting of four LaBr3(Ce) detectors, connected to a CAEN V1730 digitizer, implementing online interpolation constant fraction discrimination for picosecond-precise timestamp determination. Using the definition of the time-walk curve, the lifetime of the 21+ (344 keV) state in 152Gd was re-measured, resulting in τ(21+)=46.9(3) ps. Compared to the previously adopted lifetime the uncertainty is reduced by an order of magnitude. This improved lifetime is of significant importance for electronic fast-timing lifetime measurements, and the impact on the systematic correction procedure and lifetime measurements in the low picosecond regime are discussed.
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Simultaneous gamma-ray and electron spectroscopy of 182,184,186Hg isotopes. Stryjczyk, M.; Andel, B.; Cubiss, J. G.; Rezynkina, K.; Rodr\'{i}guez, T. R.; Garc\'{i}a-Ramos, J. E.; Andreyev, A. N.; Pakarinen, J.; Van Duppen, P.; Antalic, S.; Berry, T.; Borge, M. J. G.; Clisu, C.; Cox, D. M.; De Witte, H.; Fraile, L. M.; Fynbo, H. O. U.; Gaffney, L. P.; Harkness-Brennan, L. J.; Huyse, M.; Illana, A.; Judson, D. S.; Konki, J.; Kurcewicz, J.; Lazarus, I.; Lica, R.; Madurga, M.; Marginean, N.; Marginean, R.; Mihai, C.; Mosat, P.; Nacher, E.; Negret, A.; Ojala, J.; Ovejas, J. D.; Page, R. D.; Papadakis, P.; Pascu, S.; Perea, A.; Podolyák, Zs.; Próchniak, L.; Pucknell, V.; Rapisarda, E.; Rotaru, F.; Sotty, C.; Tengblad, O.; Vedia, V.; Vi nals, S.; Wadsworth, R.; Warr, N.; Wrzosek-Lipska, K. in Phys. Rev. C (2023). 108(1) 014308.
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Systematic investigation of time walk and time resolution characteristics of CAEN digitizers V1730 and V1751 for application to fast-timing lifetime measurement. Harter, A.; Weinert, M.; Knafla, L.; Régis, J.-M.; Esmaylzadeh, A.; Ley, M.; Jolie, J. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2023). 1053 168356.
The timing performance of the integrated digital constant fraction discriminators of the two digitizer modules V1730 and V1751 from CAEN are systematically investigated with respect to fast-timing lifetime measurements. Systematic and parameter-dependent knowledge of the time walk behavior and the time resolution of the digital constant fraction discriminators is obtained. Understanding these dependencies is crucial for properly calibrating individual fast-timing systems and a comparable investigation of these digitizers was never conducted before. Reference is made to the existing analog standard for fast-timing techniques and recent digital developments. The study shows, that the timing performance of both modules is comparable to other digital fast-timing implementations and established fast-timing setups using analog constant fraction discriminators, but with the added benefit of digital processing. The peculiarities of the modules are pointed out and described. Both digitizer modules were found to be highly effective and user-friendly instruments for modern fast-timing requirements. Best parameter sets for both digitizers as well as best energy application ranges are provided.
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Axial and triaxial degrees of freedom in 72Zn. Hellgartner, S.; Mücher, D.; Wimmer, K.; Bildstein, V.; Egido, J.L.; Gernhäuser, R.; Krücken, R.; Nowak, A.K.; Zielińska, M.; Bauer, C.; Benito, M.L.L.; Bottoni, S.; {De Witte}, H.; Elseviers, J.; Fedorov, D.; Flavigny, F.; Illana, A.; Klintefjord, M.; Kröll, T.; Lutter, R.; Marsh, B.; Orlandi, R.; Pakarinen, J.; Raabe, R.; Rapisarda, E.; Reichert, S.; Reiter, P.; Scheck, M.; Seidlitz, M.; Siebeck, B.; Siesling, E.; Steinbach, T.; Stora, T.; Vermeulen, M.; Voulot, D.; Warr, N.; Wenander, F.J.C. in Physics Letters B (2023). 841 137933.
The unstable N=42 nucleus 72Zn has been studied using multiple safe Coulomb excitation in inverse kinematics. The experiment was performed at the REX-ISOLDE facility at CERN making first use of the silicon detector array C-REX in combination with the γ-ray spectrometer Miniball. The high angular coverage of C-REX allowed to determine the reduced transition strengths for the decay of the yrast 01+, 21+ and 41+ as well as of the 02+ and 22+ states in 72Zn. The quadrupole moments of the 21+, 41+ and 22+ states were extracted. Using model independent quadrupole invariants, the ground state of 72Zn was found to have an average deformation in the γ degree of freedom close to maximum triaxiality. In comparison to experimental data in zinc isotopes with N<40, the collectivity of the 41+ state in neutron-rich 72Zn is significantly larger, indicating a collective yrast band based on the ground state of 72Zn. In contrast, a low experimental B(E2;02+→21+) strength was determined, indicating a different structure for the 02+ state. Shell-model calculations propose a 02+ state featuring a larger fraction of the (spherical) N=40 closed-shell configuration in its wave function than for the 01+ ground state. The results were also compared with beyond mean field calculations which corroborate the large deformation in the γ degree of freedom, while pointing to a more deformed 02+ state. These experimental and theoretical findings establish the importance of the γ degree of freedom in the ground state of 72Zn, located between the 68,70Ni nuclei that have spherical ground states, and 76Ge, which has a rigid triaxial shape.
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Quadrupole and octupole collectivity in the semi-magic nucleus ²⁰⁶Hg. Morrison, L.; Hadyńska-Klȩk, K.; Podolyák, Zs.; Gaffney, L.P.; Zielińska, M.; Brown, B.A.; Grawe, H.; Stevenson, P.D.; Berry, T.; Boukhari, A.; Brunet, M.; Canavan, R.; Catherall, R.; Cederkäll, J.; Colosimo, S.J.; Cubiss, J.G.; Witte, H. De; Doherty, D.T.; Fransen, Ch.; Georgiev, G.; Giannopoulos, E.; Górska, M.; Hess, H.; Kaya, L.; Kröll, T.; Lalović, N.; Marsh, B.; Palenzuela, Y. Martinez; O'Neill, G.; Pakarinen, J.; Ramos, J.P.; Reiter, P.; Rodriguez, J.A.; Rosiak, D.; Rothe, S.; Rudigier, M.; Siciliano, M.; Simpson, E.C.; Snall, J.; Spagnoletti, P.; Thiel, S.; Warr, N.; Wenander, F.; Zidarova, R. in Physics Letters B (2023). 838 137675.
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Testing the predictive power of realistic shell model calculations via lifetime measurement of the 11/2+ state in 131Sb. Bottoni, S.; Gamba, E. R.; De Gregorio, G.; Gargano, A.; Leoni, S.; Fornal, B.; Brancadori, N.; Ciconali, G.; Crespi, F. C. L.; Cieplicka-Oryńczak, N.; Iskra, Ł. W.; Colombi, G.; Kim, Y. H.; Köster, U.; Michelagnoli, C.; Dunkel, F.; Esmaylzadeh, A.; Gerhard, L.; Jolie, J.; Knafla, L.; Ley, M.; Régis, J.-M.; Schomaker, K.; Sferrazza, M. in Phys. Rev. C (2023). 107(1) 014322.
The lifetime of the 11/2+1 state in the 131Sb nucleus was measured at the LOHENGRIN spectrometer of the Institut Laue-Langevin via neutron-induced fission of 235U using γ-ray fast-timing techniques. The obtained value of T1/2=3(2) ps, at the edge of the sensitivity of the experimental method, is the first result for the 11/2+1 state half-life in neutron-rich Sb isotopes. The corresponding quadrupole reduced transition probability to the ground state is B(E2)=1.4+1.5−0.6W.u., indicating a noncollective nature of this state. Realistic shell-model calculations performed in a large valence space reproduce well the experimental value and point to a dominant 2+(130Sn)⊗πg7/2 configuration for the 11/2+1 state, as expected in a weak-coupling scenario. At the same time, the sum of the quadrupole strength of the multiplet states is predicted to exceed the one of the 130Sn core as a consequence of the equal contribution of the proton and the proton-neutron quadrupole matrix elements, pointing to possible development of collectivity already in the close neighborhood of 132Sn.
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Coulomb excitation of 74,76Zn. Illana, A.; Zielińska, M.; Huyse, M.; Rapisarda, E.; Van Duppen, P.; Wrzosek-Lipska, K.; Lenzi, S. M.; Nowacki, F.; Dao, D. D.; Otsuka, T.; Tsunoda, Y.; Arnswald, K.; Borge, M. J. G.; Cederkäll, J.; Chrysalidis, K.; Cortès, M. L.; Cox, D. M.; Day Goodacre, T.; De Witte, H.; Doherty, D. T.; Fedosseev, V.; Gaffney, L. P.; Hadyńska-Klẹk, K.; Hess, H.; Henrich, C.; Hlebowicz, M.; Komorowska, M.; Korten, W.; Kröll, Th.; Lozano Benito, M. L.; Lutter, R.; Marsh, B.; Martikainen, L.; Matejska-Minda, M.; Molkanov, P. L.; Nacher, E.; Nannini, A.; Napiorkowski, P. J.; Pakarinen, J.; Papadakis, P.; Queiser, M.; Reiter, P.; Rocchini, M.; Rodriguez, J. A.; Rolke, T.; Rosiak, D.; Rothe, S.; Seidlitz, M.; Seiffert, C.; Siebeck, B.; Siesling, E.; Snäll, J.; Srebrny, J.; Thiel, S.; Warr, N.; Wenander, F. in Phys. Rev. C (2023). 108(4) 044305.
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In-beam gamma-ray spectroscopy of 94Ag. Pereira-L{ó}pez, X.; Bentley, M. A.; Wadsworth, R.; Ruotsalainen, P.; Lenzi, S. M.; Forsberg, U.; Auranen, K.; Blazhev, A.; Cederwall, B.; Grahn, T.; Greenlees, P.; Illana, A.; Jenkins, D. G.; Julin, R.; Jutila, H.; Juutinen, S.; Liu, X.; Llewelyn, R.; Luoma, M.; Moschner, K.; M{ü}ller-Gatermann, C.; Singh, B. S. Nara; Nowacki, F.; Ojala, J.; Pakarinen, J.; Papadakis, P.; Rahkila, P.; Romero, J.; Sandzelius, M.; Sar{é}n, J.; Tann, H.; Uthayakumaar, S.; Uusitalo, J.; Vega-Romero, J. G.; Vilhena, J. M.; Yajzey, R.; Zhang, W.; Zimba, G. in The European Physical Journal A (2023). 59(3) 44.
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Studying Gamow-Teller transitions and the assignment of isomeric and ground states at N = 50. Mollaebrahimi, Ali; Hornung, Christine; Dickel, Timo; Amanbayev, Daler; Kripko-Koncz, Gabriella; Plaß, Wolfgang R.; {Ayet San Andrés}, Samuel; Beck, Sönke; Blazhev, Andrey; Bergmann, Julian; Geissel, Hans; Górska, Magdalena; Grawe, Hubert; Greiner, Florian; Haettner, Emma; Kalantar-Nayestanaki, Nasser; Miskun, Ivan; Nowacki, Frédéric; Scheidenberger, Christoph; Bagchi, Soumya; Balabanski, Dimiter L.; Brencic, Ziga; Charviakova, Olga; Constantin, Paul; Dehghan, Masoumeh; Ebert, Jens; Gröf, Lizzy; Hall, Oscar; Harakeh, Muhsin N.; Kaur, Satbir; Kankainen, Anu; Knöbel, Ronja; Kostyleva, Daria A.; Kurkova, Natalia; Kuzminchuk, Natalia; Mardor, Israel; Nichita, Dragos; Otto, Jan-Hendrik; Patyk, Zygmunt; Pietri, Stephane; Purushothaman, Sivaji; Reiter, Moritz Pascal; Rink, Ann-Kathrin; Roesch, Heidi; Spătaru, Anamaria; Stanic, Goran; State, Alexandru; Tanaka, Yoshiki K.; Vencelj, Matjaz; Weick, Helmut; Winfield, John S.; Yavor, Michael I.; Zhao, Jianwei in Physics Letters B (2023). 839 137833.
Direct mass measurements of neutron-deficient nuclides around the N=50 shell closure below 100Sn were performed at the FRS Ion Catcher (FRS-IC) at GSI, Germany. The nuclei were produced by projectile fragmentation of 124Xe, separated in the fragment separator FRS and delivered to the FRS-IC. The masses of 14 ground states and two isomers were measured with relative mass uncertainties down to 1×10−7 using the multiple-reflection time-of-flight mass spectrometer of the FRS-IC, including the first direct mass measurements of 98Cd and 97Rh. A new QEC=5437±67 keV was obtained for 98Cd, resulting in a summed Gamow-Teller (GT) strength for the five observed transitions (0+⟶1+) as B(GT)=2.94−0.28+0.32. Investigation of this result in state-of-the-art shell model approaches accounting for the first time experimentally observed spectrum of GT transitions points to a perfect agreement for N=50 isotones. The excitation energy of the long-lived isomeric state in 94Rh was determined for the first time to be 293±21 keV. This, together with the shell model calculations, allows the level ordering in 94Rh to be understood.
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The non-destructive investigation of a late antique knob bow fibula (Bügelknopffibel) from Kaiseraugst/{CH} using Muon Induced X-ray Emission ({MIXE}). Biswas, Sayani; Megatli-Niebel, Isabel; Raselli, Lilian; Simke, Ronald; Cocolios, Thomas Elias; Deokar, Nilesh; Elender, Matthias; Gerchow, Lars; Hess, Herbert; Khasanov, Rustem; Knecht, Andreas; Luetkens, Hubertus; Ninomiya, Kazuhiko; Papa, Angela; Prokscha, Thomas; Reiter, Peter; Sato, Akira; Severijns, Nathal; Shiroka, Toni; Seidlitz, Michael; Vogiatzi, Stergiani Marina; Wang, Chennan; Wauters, Frederik; Warr, Nigel; Amato, Alex in Heritage Science (2023). 11(1)
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Study of N=50 gap evolution around Z=32: new structure information for 82Ge. Thisse, D.; Lebois, M.; Verney, D.; Wilson, J. N.; Jovancević, N.; Rudigier, M.; Canavan, R.; Etasse, D.; Adsley, P.; Algora, A.; Babo, M.; Belvedere, K.; Benito, J.; Benzoni, G.; Blazhev, A.; Boso, A.; Bottoni, S.; Bunce, M.; Chakma, R.; Cieplicka-Oryńczak, N.; Courtin, S.; Cortés, M. L.; Davies, P.; Delafosse, C.; Fallot, M.; Fornal, B.; Fraile, L.; Gjestvang, D.; Gottardo, A.; Guadilla, V.; Gerst, R. B.; Häfner, G.; Hauschild, K.; Heine, M.; Henrich, C.; Homm, I.; Hommet, J.; Ibrahim, F.; Iskra, Ł. W.; Ivanov, P.; Jazrawi, S.; Korgul, A.; Koseoglou, P.; Kröll, T.; Kurtukian-Nieto, T.; Meur, L. Le; Leoni, S.; Ljungvall, J.; Lopez-Martens, A.; Lozeva, R.; Matea, I.; Miernik, K.; Nemer, J.; Oberstedt, S.; Paulsen, W.; Piersa-Silkowska, M.; Poklepa, W.; Popovitch, Y.; Porzio, C.; Qi, L.; Ralet, D.; Regan, P. H.; Reygadas-Tello, D.; Rezynkina, K.; Sánchez-Tembleque, V.; Siem, S.; Schmitt, C.; Söderström, P. A.; Solak, K.; Sürder, C.; Tocabens, G.; Vedia, V.; Warr, N.; Wasilewska, B.; Wiederhold, J.; Yavahchova, M.; Zeiser, F.; Ziliani, S. in The European Physical Journal A (2023). 59(7)
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Characterization of a Continuous Muon Source for the Non-Destructive and Depth-Selective Elemental Composition Analysis by Muon Induced X- and Gamma-rays. Biswas, Sayani; Gerchow, Lars; Luetkens, Hubertus; Prokscha, Thomas; Antognini, Aldo; Berger, Niklaus; Cocolios, Thomas Elias; Dressler, Rugard; Indelicato, Paul; Jungmann, Klaus; Kirch, Klaus; Knecht, Andreas; Papa, Angela; Pohl, Randolf; Pospelov, Maxim; Rapisarda, Elisa; Reiter, Peter; Ritjoho, Narongrit; Roccia, Stephanie; Severijns, Nathal; Skawran, Alexander; Vogiatzi, Stergiani Marina; Wauters, Frederik; Willmann, Lorenz; Amato, Alex in Applied Sciences (2022). 12(5) 2541.
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Lifetime measurements in the ground-state band in ¹⁰⁴Pd. Droste, M.; Blazhev, A.; Reiter, P.; Arnswald, K.; Beckers, M.; Fransen, C.; Hetzenegger, R.; Hirsch, R.; Kaya, L.; Knafla, L.; Lewandowski, L.; Müller-Gatermann, C.; Petkov, P.; Rosiak, D.; Seidlitz, M.; Siebeck, B.; Vogt, A.; Warr, N.; Wolf, K. in Phys. Rev. C (2022). 106(2) 024329.
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Coulomb excitation of ²²²Rn. Spagnoletti, P.; Butler, P. A.; Gaffney, L. P.; Abrahams, K.; Bowry, M.; Cederkäll, J.; Chupp, T.; de Angelis, G.; De Witte, H.; Garrett, P. E.; Goldkuhle, A.; Henrich, C.; Illana, A.; Johnston, K.; Joss, D. T.; Keatings, J. M.; Kelly, N. A.; Komorowska, M.; Konki, J.; Kröll, T.; Lozano, M.; Singh, B. S. Nara; O'Donnell, D.; Ojala, J.; Page, R. D.; Pedersen, L. G.; Raison, C.; Reiter, P.; Rodriguez, J. A.; Rosiak, D.; Rothe, S.; Scheck, M.; Seidlitz, M.; Shneidman, T. M.; Siebeck, B.; Sinclair, J.; Smith, J. F.; Stryjczyk, M.; Van Duppen, P.; Viñals, S.; Virtanen, V.; Wrzosek-Lipska, K.; Warr, N.; Zielińska, M. in Phys. Rev. C (2022). 105(2) 024323.
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Evidence for spherical-oblate shape coexistence in ⁸⁷Tc. Liu, X.; Cederwall, B.; Qi, C.; Wyss, R. A.; Aktas, Ö.; Ertoprak, A.; Zhang, W.; Clément, E.; de France, G.; Ralet, D.; Gadea, A.; Goasduff, A.; Jaworski, G.; Kuti, I.; Nyakó, B. M.; Nyberg, J.; Palacz, M.; Wadsworth, R.; Valiente-Dobón, J. J.; Al-Azri, H.; Ataç Nyberg, A.; Bäck, T.; de Angelis, G.; Doncel, M.; Dudouet, J.; Gottardo, A.; Jurado, M.; Ljungvall, J.; Mengoni, D.; Napoli, D. R.; Petrache, C. M.; Sohler, D.; Timár, J.; Barrientos, D.; Bednarczyk, P.; Benzoni, G.; Birkenbach, B.; Boston, A. J.; Boston, H. C.; Burrows, I.; Charles, L.; Ciemala, M.; Crespi, F. C. L.; Cullen, D. M.; Désesquelles, P.; Domingo-Pardo, C.; Eberth, J.; Erduran, N.; Ertürk, S.; González, V.; Goupil, J.; Hess, H.; Huyuk, T.; Jungclaus, A.; Korten, W.; Lemasson, A.; Leoni, S.; Maj, A.; Menegazzo, R.; Million, B.; Perez-Vidal, R. M.; Podolyàk, Zs.; Pullia, A.; Recchia, F.; Reiter, P.; Saillant, F.; Salsac, M. D.; Sanchis, E.; Simpson, J.; Stezowski, O.; Theisen, C.; Zielińska, M. in Phys. Rev. C (2022). 106(3) 034304.
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New narrow resonances observed in the unbound nucleus ¹⁵F. Girard-Alcindor, V.; Mercenne, A.; Stefan, I.; de Oliveira Santos, F.; Michel, N.; Płoszajczak, M.; Assié, M.; Lemasson, A.; Clément, E.; Flavigny, F.; Matta, A.; Ramos, D.; Rejmund, M.; Dudouet, J.; Ackermann, D.; Adsley, P.; Assunção, M.; Bastin, B.; Beaumel, D.; Benzoni, G.; Borcea, R.; Boston, A. J.; Brugnara, D.; Cáceres, L.; Cederwall, B.; Celikovic, I.; Chudoba, V.; Ciemala, M.; Collado, J.; Crespi, F. C. L.; D'Agata, G.; De France, G.; Delaunay, F.; Diget, C.; Domingo-Pardo, C.; Eberth, J.; Fougères, C.; Franchoo, S.; Galtarossa, F.; Georgiadou, A.; Gibelin, J.; Giraud, S.; González, V.; Goyal, N.; Gottardo, A.; Goupil, J.; Grévy, S.; Guimaraes, V.; Hammache, F.; Harkness-Brennan, L. J.; Hess, H.; Jovančević, N.; Judson Oliver, D. S.; Kamalou, O.; Kamenyero, A.; Kiener, J.; Korten, W.; Koyama, S.; Labiche, M.; Lalanne, L.; Lapoux, V.; Leblond, S.; Lefevre, A.; Lenain, C.; Leoni, S.; Li, H.; Lopez-Martens, A.; Maj, A.; Matea, I.; Menegazzo, R.; Mengoni, D.; Meyer, A.; Million, B.; Monteagudo, B.; Morfouace, P.; Mrazek, J.; Niikura, M.; Piot, J.; Podolyak, Zs.; Portail, C.; Pullia, A.; Quintana, B.; Recchia, F.; Reiter, P.; Rezynkina, K.; Roger, T.; Rojo, J. S.; Rotaru, F.; Salsac, M. D.; Sánchez Benítez, A. M.; Sanchis, E.; Şienyigit, M.; de Séréville, N.; Siciliano, M.; Simpson, J.; Sohler, D.; Sorlin, O.; Stanoiu, M.; Stodel, C.; Suzuki, D.; Theisen, C.; Thisse, D.; C.Thomas, J.; Ujic, P.; Valiente-Dobón, J. J.; Zielińska, M. in Phys. Rev. C (2022). 105(5) L051301.
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The DESPEC setup for GSI and FAIR. Mistry, A.K.; Albers, H.M.; Arıcı, T.; Banerjee, A.; Benzoni, G.; Cederwall, B.; Gerl, J.; Górska, M.; Hall, O.; Hubbard, N.; Kojouharov, I.; Jolie, J.; Martinez, T.; Podolyák, Zs.; Regan, P.H.; Tain, J.L.; Tarifeno-Saldivia, A.; Schaffner, H.; Werner, V.; Ağgez, G.; Agramunt, J.; Ahmed, U.; Aktas, O.; Alcayne, V.; Algora, A.; Alhomaidhi, S.; Amjad, F.; Appleton, C.; Armstrong, M.; Balogh, M.; Banerjee, K.; Bednarczyk, P.; Benito, J.; Bhattacharya, C.; Black, P.; Blazhev, A.; Bottoni, S.; Boutachkov, P.; Bracco, A.; Bruce, A.M.; Brunet, M.; Bruno, C.G.; Burrows, I.; Calvino, F.; Canavan, R.L.; Cano-Ott, D.; Chishti, M.M.R.; Coleman-Smith, P.; Cortés, M.L.; Cortes, G.; Crespi, F.; Das, B.; Davinson, T.; De Blas, A.; Dickel, T.; Doncel, M.; Ertoprak, A.; Esmaylzadeh, A.; Fornal, B.; Fraile, L.M.; Galtarossa, F.; Gottardo, A.; Guadilla, V.; Ha, J.; Haettner, E.; Häfner, G.; Heggen, H.; Herrmann, P.; Hornung, C.; Jazrawi, S.; John, P.R.; Jokinen, A.; Jones, C.E.; Kahl, D.; Karayonchev, V.; Kazantseva, E.; Kern, R.; Knafla, L.; Knöbel, R.; Koseoglou, P.; Kosir, G.; Kostyleva, D.; Kurz, N.; Kuzminchuk, N.; Labiche, M.; Lawson, J.; Lazarus, I.; Lenzi, S.M.; Leoni, S.; Llanos-Expósito, M.; Lozeva, R.; Maj, A.; Meena, J.K.; Mendoza, E.; Menegazzo, R.; Mengoni, D.; Mertzimekis, T.J.; Mikolajczuk, M.; Million, B.; Mont-Geli, N.; Morales, A.I.; Morral, P.; Mukha, I.; Murias, J.R.; Nacher, E.; Napiralla, P.; Napoli, D.R.; Nara-Singh, B.S.; O’Donnell, D.; Orrigo, S.E.A.; Page, R.D.; Palit, R.; Pallas, M.; Pellumaj, J.; Pelonis, S.; Pentilla, H.; Pérez de Rada, A.; Pérez-Vidal, R.M.; Petrache, C.M.; Pietralla, N.; Pietri, S.; Pigliapoco, S.; Plaza, J.; Polettini, M.; Porzio, C.; Pucknell, V.F.E.; Recchia, F.; Reiter, P.; Rezynkina, K.; Rinta-Antila, S.; Rocco, E.; Rösch, H.A.; Roy, P.; Rubio, B.; Rudigier, M.; Ruotsalainen, P.; Saha, S.; Şahin, E.; Scheidenberger, Ch.; Seddon, D.A.; Sexton, L.; Sharma, A.; Si, M.; Simpson, J.; Smith, A.; Smith, R.; Söderström, P.A.; Sood, A.; Soylu, A.; Tanaka, Y.K.; Valiente-Dobón, J.J.; Vasileiou, P.; Vasiljevic, J.; Vesic, J.; Villamarin, D.; Weick, H.; Wiebusch, M.; Wiederhold, J.; Wieland, O.; Wollersheim, H.J.; Woods, P.J.; Yaneva, A.; Zanon, I.; Zhang, G.; Zhao, J.; Zidarova, R.; Zimba, G.; Zyriliou, A. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2022). 1033 166662.
The DEcay SPECtroscopy (DESPEC) setup for nuclear structure investigations was developed and commissioned at GSI, Germany in preparation for a full campaign of experiments at the FRS and Super-FRS. In this paper, we report on the first employment of the setup in the hybrid configuration with the AIDA implanter coupled to the FATIMA LaBr3(Ce) fast-timing array, and high-purity germanium detectors. Initial results are shown from the first experiments carried out with the setup. An overview of the setup and function is discussed, including technical advancements along the path.
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Development of a new γ–γ angular correlation analysis method using a symmetric ring of clover detectors. Knafla, L.; Esmaylzadeh, A.; Harter, A.; Jolie, J.; Köster, U.; Ley, M.; Michelagnoli, C.; Régis, J.-M. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2022). 1042 167463.
A new method for γ–γ angular correlation analysis using a symmetric ring of HPGe clover detectors is presented. Pairwise combinations of individual crystals are grouped based on the geometric properties of the spectrometer, constrained by a single variable parameterization based on symmetry considerations. The corresponding effective interaction angles between crystal pairs, as well as the attenuation coefficients are extracted directly from the measured experimental data. Angular correlation coefficients, parameter uncertainties and parameter co-variances are derived using a Monte-Carlo approach, considering all sources of statistical uncertainty. The general applicability of this approach is demonstrated by reproducing known multipole mixing ratios in 177Hf, 152Gd and 116Sn, populated by either β-decay or (n, γ)-reactions, measured at the Institut Laue-Langevin, using the EXILL&FATIMA spectrometer and different configurations of the FIPPS instrument. The derived mixing ratios are in excellent agreement with adopted literature values with comparable or better precision.
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Gamma-ray spectroscopy of low-lying yrast and non-yrast states in neutron-rich 94,95,96Kr. Gerst, R.-B.; Blazhev, A.; Moschner, K.; Doornenbal, P.; Obertelli, A.; Nomura, K.; Ebran, J.-P.; Hilaire, S.; Libert, J.; Authelet, G.; Baba, H.; Calvet, D.; Château, F.; Chen, S.; Corsi, A.; Delbart, A.; Gheller, J.-M.; Giganon, A.; Gillibert, A.; Lapoux, V.; Motobayashi, T.; Niikura, M.; Paul, N.; Roussé, J.-Y.; Sakurai, H.; Santamaria, C.; Steppenbeck, D.; Taniuchi, R.; Uesaka, T.; Ando, T.; Arici, T.; Browne, F.; Bruce, A. M.; Caroll, R.; Chung, L. X.; Cortés, M. L.; Dewald, M.; Ding, B.; Flavigny, F.; Franchoo, S.; Górska, M.; Gottardo, A.; Jolie, J.; Jungclaus, A.; Lee, J.; Lettmann, M.; Linh, B. D.; Liu, J.; Liu, Z.; Lizarazo, C.; Momiyama, S.; Nagamine, S.; Nakatsuka, N.; Nita, C. R.; Nobs, C.; Olivier, L.; Orlandi, R.; Patel, Z.; Podolyák, Zs.; Rudigier, M.; Saito, T.; Shand, C.; Söderström, P.-A.; Stefan, I.; Vaquero, V.; Werner, V.; Wimmer, K.; Xu, Z. in Phys. Rev. C (2022). 105(2) 024302.
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Lifetime measurements in the tungsten isotopes 176,178,180W. Harter, A.; Knafla, L.; Frießner, G.; Häfner, G.; Jolie, J.; Blazhev, A.; Dewald, A.; Dunkel, F.; Esmaylzadeh, A.; Fransen, C.; Karayonchev, V.; Lawless, K.; Ley, M.; Régis, J.-M.; Zell, K. O. in Phys. Rev. C (2022). 106(2) 024326.
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Evidence of Partial Seniority Conservation in the πg9/2 Shell for the N=50 Isotones. Pérez-Vidal, R. M.; Gadea, A.; Domingo-Pardo, C.; Gargano, A.; Valiente-Dobón, J. J.; Clément, E.; Lemasson, A.; Coraggio, L.; Siciliano, M.; Szilner, S.; Bast, M.; Braunroth, T.; Collado, J.; Corina, A.; Dewald, A.; Doncel, M.; Dudouet, J.; de France, G.; Fransen, C.; González, V.; Hüyük, T.; Jacquot, B.; John, P. R.; Jungclaus, A.; Kim, Y. H.; Korichi, A.; Labiche, M.; Lenzi, S.; Li, H.; Ljungvall, J.; López-Martens, A.; Mengoni, D.; Michelagnoli, C.; Müller-Gatermann, C.; Napoli, D. R.; Navin, A.; Quintana, B.; Ramos, D.; Rejmund, M.; Sanchis, E.; Simpson, J.; Stezowski, O.; Wilmsen, D.; Zielińska, M.; Boston, A. J.; Barrientos, D.; Bednarczyk, P.; Benzoni, G.; Birkenbach, B.; Boston, H. C.; Bracco, A.; Cederwall, B.; Cullen, D. M.; Didierjean, F.; Eberth, J.; Gottardo, A.; Goupil, J.; Harkness-Brennan, L. J.; Hess, H.; Judson, D. S.; Kaşkaş, A.; Korten, W.; Leoni, S.; Menegazzo, R.; Million, B.; Nyberg, J.; Podolyak, Zs.; Pullia, A.; Ralet, D.; Recchia, F.; Reiter, P.; Rezynkina, K.; Salsac, M. D.; Şenyiğit, M.; Sohler, D.; Theisen, Ch.; Verney, D. in Phys. Rev. Lett. (2022). 129(11) 112501.
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Investigation of gamma softness: Lifetime measurements in 104,106Ru. Esmaylzadeh, A.; Blazhev, A.; Nomura, K.; Jolie, J.; Beckers, M.; Fransen, C.; Gerst, R.-B.; Harter, A.; Karayonchev, V.; Knafla, L.; Ley, M.; von Spee, F. in Phys. Rev. C (2022). 106(6) 064323.
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Nature of seniority symmetry breaking in the semimagic nucleus 94Ru. Das, B.; Cederwall, B.; Qi, C.; Górska, M.; Regan, P. H.; Aktas, Ö.; Albers, H. M.; Banerjee, A.; Chishti, M. M. R.; Gerl, J.; Hubbard, N.; Jazrawi, S.; Jolie, J.; Mistry, A. K.; Polettini, M.; Yaneva, A.; Alhomaidhi, S.; Zhao, J.; Arici, T.; Bagchi, S.; Benzoni, G.; Boutachkov, P.; Davinson, T.; Dickel, T.; Haettner, E.; Hall, O.; Hornung, Ch.; Hucka, J. P.; John, P. R.; Kojouharov, I.; Knöbel, R.; Kostyleva, D.; Kuzminchuk, N.; Mukha, I.; Plass, W. R.; Nara Singh, B. S.; Vasiljevi ́c, J.; Pietri, S.; Podolyák, Zs.; Rudigier, M.; Rösch, H.; Sahin, E.; Schaffner, H.; Scheidenberger, C.; Schirru, F.; Sharma, A.; Shearman, R.; Tanaka, Y.; Vesi ́c, J.; Weick, H.; Wollersheim, H. J.; Ahmed, U.; Algora, A.; Appleton, C.; Benito, J.; Blazhev, A.; Bracco, A.; Bruce, A. M.; Brunet, M.; Canavan, R.; Esmaylzadeh, A.; Fraile, L. M.; Häfner, G.; Heggen, H.; Kahl, D.; Karayonchev, V.; Kern, R.; Korgul, A.; Kosir, G.; Kurz, N.; Lozeva, R.; Mikolajczuk, M.; Napiralla, P.; Page, R.; Petrache, C. M.; Pietralla, N.; Régis, J.-M.; Ruotsalainen, P.; Sexton, L.; Sanchez-Temble, V.; Si, M.; Vilhena, J.; Werner, V.; Wiederhold, J.; Witt, W.; Woods, P. J.; Zimba, G. in Phys. Rev. C (2022). 105(3) L031304.
Direct lifetime measurements via γ−γ coincidences using a fast timing detector array consisting of LaBr3(Ce) scintillators has been applied to determine the lifetime of low-lying states in the semimagic (N=50) nucleus 94Ru. The experiment was carried out as the first in a series of “FAIR-0” experiments with the DESPEC experimental setup at the Facility for Antiproton and Ion Research (FAIR). Excited states in 94Ru were populated primarily via the β-delayed proton emission of 95Pd nuclei, produced in the projectile fragmentation of an 850 MeV/nucleon 124Xe beam impinging on a 4 g/cm29Be target. While the deduced E2 strength for the 2+→0+ transition in the yrast cascade follows the expected behavior for conserved seniority symmetry, the intermediate 4+→2+ transition exhibits a drastic enhancement of transition strength in comparison with pure-seniority model predictions as well as standard shell model predictions in the fpg proton hole space with respect to doubly magic 100Sn. The anomalous behavior is ascribed to a subtle interference between the wave function of the lowest seniority ν=2, Iπ=4+ state and that of a close-lying ν=4 state that exhibits partial dynamic symmetry. In addition, the observed strongly prohibitive 6+→4+ transition can be attributed to the same mechanism but with a destructive interference. It is noted that such effects may provide stringent tests of the nucleon-nucleon interactions employed in state-of-the-art theoretical model calculations.
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Lifetime measurements to investigate γ softness and shape coexistence in 102Mo. Esmaylzadeh, A.; Karayonchev, V.; Nomura, K.; Jolie, J.; Beckers, M.; Blazhev, A.; Dewald, A.; Fransen, C.; Gerst, R.-B.; Häfner, G.; Harter, A.; Knafla, L.; Ley, M.; Robledo, L. M.; Rodríguez-Guzmán, R.; Rudigier, M. in Phys. Rev. C (2021). 104(6) 064314.
Lifetimes of low-spin excited states in 102Mo populated in a 100Mo(18O,16O)102Mo two-neutron transfer reaction were measured using the recoil-distance Doppler-shift technique at the Cologne FN Tandem accelerator. Lifetimes of the 2+1, 4+1, 6+1, 0+2, 2+γ, 3+γ states and one upper limit for the lifetime of the 4+γ state were obtained. The energy levels and deduced electromagnetic transition probabilities are compared with those obtained within the mapped interacting boson model framework with microscopic input from Gogny mean-field calculations. With the newly obtained signatures a more detailed insight in the γ softness and shape coexistence in 102Mo is possible and discussed in the context of the Z≈40 and N≈60 region. The nucleus of 102Mo follows the γ soft trend of the Mo isotopes. The properties of the 0+2 state indicate, in contrast with the microscopic predictions, shape coexistence which also occurs in other N=60 isotones.
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In search of nano-materials with enhanced secondary electron emission for radiation detectors. Cholewa, M;; Cappellazzo, M;; Ley, M;; Bittner, D;; Jolie, J;; Lee, K;; Song, M;; Yi, G;; Boutachkov, P; in Nature Scientific Reports (2021). 11(10517)
There has been limited research devoted to secondary electron emission (SEE) from nano-materials using rapid and heavy ion bombardment. Here we report a comparison of SEE properties between novel nano-materials with a three-dimensional nano-structure composed of a mostly regular pattern of rods and gold used as a standard material for SEE under bombardment of heavy ions at energies of a few MeV/nucleon. The nano-structured materials show enhanced SEE properties when compared with gold. Results from this work will enable the development of new radiation detectors for science and industry.
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Lifetimes and structures of low-lying negative-parity states of 209Po. Karayonchev, V.; Stoyanova, M.; Rainovski, G.; Jolie, J.; Blazhev, A.; Djongolov, M.; Esmaylzadeh, A.; Fransen, C.; Gladnishki, K.; Knafla, L.; Kocheva, D.; Kornwebel, L.; Régis, J.-M.; De Gregorio, G.; Gargano, A. in Phys. Rev. C (2021). 103(4) 044309.
The 5/2−1, 9/2−1, and 11/2−1 states in 209Po were populated in the β decay of 209At and their lifetimes measured using the electronic γ−γ fast timing technique. The lifetime of the 9/2−1 state is measured for first time. The lifetime of the 5/2−1 is measured to be shorter than the value adopted in the literature while the lifetime of the 11/2−1 state agrees well with the previous measurement. In order to get deeper insight into the structure of the states, a shell-model calculation was carried out adopting a microscopic effective interaction derived from the realistic CD-Bonn potential. The comparison between theoretical and experimental data for the low-lying negative-parity states of 209Po supports the reliability of the predicted wave functions, which are found to be dominated by the coupling of a neutron hole to the yrast states of 210Po. However, it also points to the important role played by minor wave-function components in describing the reduced electromagnetic strengths, suggesting the need of additional configuration mixing for achieving a better quantitative agreement.
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Triaxiality in the mid-shell nucleus 112Pd. Esmaylzadeh, A.; Karayonchev, V.; Häfner, G.; Jolie, J.; Beckers, M.; Blazhev, A.; Dewald, A.; Fransen, C.; Goldkuhle, A.; Knafla, L.; Müller-Gatermann, C. in Phys. Rev. C (2021). 103(5) 054324.
Lifetimes of low-spin excited states in 112Pd were measured using the recoil-distance Doppler-shift technique. The nucleus of interest was populated in a 110 Pd(18O,16O)112Pd reaction using the Cologne FN Tandem accelerator. Three lifetimes of ground-state band members and one lifetime of the γ band were measured. From these lifetimes reduced transition probabilities were extracted and compared to interacting boson model, γ-soft calculations, and Davydov calculations. The lifetime of the 2+γ gives some insights on the nuclear shape and structure of the γ band. The deduced transition rates show an indicator for a rigid triaxial nucleus as well as more indicators for a γ-soft nucleus.
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Lifetime measurements in 182Pt using γ–γ fast-timing. Häfner, G.; Esmaylzadeh, A.; Jolie, J.; Régis, J.-M.; Müller-Gatermann, C.; Blazhev, A.; Fransen, C.; Gerst, R.-B.; Karayonchev, V.; Knafla, L.; Saed-Samii, N.; Zell, K.-O. in The European Physical Journal A (2021). 57(5) 174.
The level lifetimes of the 2+1 and 4+1 states in 182Pt have been re-measured employing the γ–γ fast-timing technique using fast LaBr3(Ce) scintillators. Excited states in the nucleus of interest were populated by the fusion-evaporation reaction 170Yb(16O,4n)182Pt at a beam energy of 87 MeV provided by the FN Tandem accelerator of the University of Cologne. The lifetime of the 2+1 state was re-measured with high accuracy to be τ=563(12) ps and resolves inconsistencies from previous measurements. Experimental results are compared to theoretical calculations in the framework of the sd-IBM with and without configuration mixing.
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Microscopic structure of the one-phonon 2+ states of 208Po. Kalaydjieva, D.; Kocheva, D.; Rainovski, G.; Karayonchev, V.; Jolie, J.; Pietralla, N.; Beckers, M.; Blazhev, A.; Dewald, A.; Djongolov, M.; Esmaylzadeh, A.; Fransen, C.; Gladnishki, K. A.; Goldkuhle, A.; Henrich, C.; Homm, I.; Ide, K. E.; John, P. R.; Kern, R.; Kleemann, J.; Kröll, Th.; Müller-Gatermann, C.; Scheck, M.; Spagnoletti, P.; Stoyanova, M.; Stoychev, K.; Werner, V.; Yaneva, A.; Dimitrova, S. S.; De Gregorio, G.; Naïdja, H.; Gargano, A. in Phys. Rev. C (2021). 104(2) 024311.
The lifetimes of the 2+1 and 4+1 states of 208Po were measured in the α-transfer reaction 204Pb(12C,8Be)208Po by γ-ray spectroscopy utilizing the recoil distance Doppler shift method. The newly extracted transition strengths alongside ones of the decay of the 2+2 state were compared to the results of large-scale shell-model calculations using an effective interaction derived from the realistic CD-Bonn nucleon-nucleon potential. The comparison indicates the importance of the quadrupole isovector excitations in the valence shell for a fine tuning of the two-body matrix elements of the shell-model interaction.
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Gamma spectroscopy with AGATA in its first phases: New insights in nuclear excitations along the nuclear chart. Bracco, A.; Duchêne, G.; Podolyák, Zs.; Reiter, P. in Progress in Particle and Nuclear Physics (2021). 121 103887.
The Advanced GAmma Tracking Array (AGATA), the new generation high-resolution γ-ray spectrometer, has seen the realization of the first phases of its construction and exploitation. A number of nuclear structure studies based on experiments utilizing the principle of γ-ray tracking were carried out in this decade. The combination of highest detection efficiency and position sensitivity allowed very selective spectroscopic studies with stable beams and the use of instable ion beams with the lowest intensities. Nuclear-structure studies commenced already at INFN-LNL (Legnaro, Italy) with a first implementation of the array consisting of five AGATA modules. A larger array of AGATA modules was used at GSI (Darmstadt, Germany) for experiments with unstable ion beams at relativistic energies. The spectrometer was then mounted in a beam line at GANIL (Caen, France). This review discusses several of the obtained results, underlying the progress made and future perspectives. The performed experiments give insights into nuclear structure issues which are connected to single particles, collective degrees of freedom, nucleon interactions and symmetries. Most of the investigated nuclei are located outside the stability line and for stable nuclei the investigations concern unexplored configurations. Altogether the obtained results represent advances which could test theory in exclusive way and motivate new theoretical developments. Opportunities for further γ-ray spectroscopy with the foreseen more advanced phase of the AGATA emerge in the discussions of the presented data.
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Reinterpretation of excited states in 212Po: Shell-model multiplets rather than α-cluster states. Fernández, A.; Jungclaus, A.; Golubev, P.; Rudolph, D.; Sarmiento, L. G.; Gargano, A.; Naïdja, H.; Astier, A.; Dupont, E.; Gadea, A.; Nácher, E.; Perea, A.; Wimmer, K.; Clément, E.; Fremont, G.; Goupil, J.; Houarner, C.; Jacquot, B.; Korichi, A.; Lemasson, A.; Li, H. J.; Ljungvall, J.; Ménager, L.; Pérez-Vidal, R. M.; Petrache, C. M.; Ralet, D.; Ropert, J. A.; Saillant, F.; Såmark-Roth, A.; Simpson, G. S.; Spitaels, C.; Zielinska, M.; Ansari, S.; Dudouet, J.; Illana, A.; Jurado, M.; Kocheva, D.; Lalović, N.; Lorenz, Ch.; Quintana, B.; Rainovski, G.; Redon, N.; Tocabens, G.; Barrientos, D.; Benzoni, G.; Birkenbach, B.; Boston, A. J.; Boston, H. C.; Bracco, A.; Ciemala, M.; Collado, J.; Cullen, D. M.; Domingo-Pardo, C.; Eberth, J.; González, V.; Harkness-Brennan, L. J.; Hess, H.; Judson, D. S.; Korten, W.; Leoni, S.; Maj, A.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Million, B.; Napoli, D. R.; Nyberg, J.; Podolyak, Zs.; Pullia, A.; Reiter, P.; Sanchis, E.; Stezowski, O.; Theisen, Ch.; Valiente-Dobón, J. J. in Phys. Rev. C (2021). 104(5) 054316.
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Competition between allowed and first-forbidden beta decays of 208At and expansion of the 208Po level scheme. Brunet, M.; Podolyák, Zs.; Berry, T. A.; Brown, B. A.; Carroll, R. J.; Lica, R.; Sotty, Ch.; Andreyev, A. N.; Borge, M. J. G.; Cubiss, J. G.; Fraile, L. M.; Fynbo, H. O. U.; Gamba, E.; Greenlees, P.; Harkness-Brennan, L. J.; Huyse, M.; Judson, D. S.; Konki, J.; Kurcewicz, J.; Lazarus, I.; Madurga, M.; Marginean, N.; Marginean, R.; Marroquin, I.; Mihai, C.; Nácher, E.; Negret, A.; Pascu, S.; Page, R. D.; Perea, A.; Phrompao, J.; Piersa, M.; Pucknell, V.; Rahkila, P.; Rapisarda, E.; Regan, P. H.; Rotaru, F.; Rudigier, M.; Shand, C. M.; Shearman, R.; Simpson, E. C.; Stora, T.; Tengblad, O.; Van Duppen, P.; Vedia, V.; Vinals, S.; Wadsworth, R.; Warr, N.; De Witte, H. in Phys. Rev. C (2021). 103(5) 054327.
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The (6+) isomer in 102Sn revisited: Neutron and proton effective charges close to the double shell closure. Grawe, H.; Straub, K.; Faestermann, T.; Górska, M.; Hinke, C.; Krücken, R.; Nowacki, F.; Böhmer, M.; Boutachkov, P.; Geissel, H.; Gernhäuser, R.; Gottardo, A.; Grȩbosz, J.; Kurz, N.; Liu, Z.; Maier, L.; Pietri, S.; Podolyák, Zs.; Steiger, K.; Weick, H.; Wollersheim, H.J.; Woods, P.J.; Al-Dahan, N.; Alkhomashi, N.; Ataç, A.; Blazhev, A.; Braun, N.; Čeliković, I.; Davinson, T.; Dillmann, I.; Domingo-Pardo, C.; Doornenbal, P.; Farrelly, G.; Farinon, F.; {de France}, G.; Gerl, J.; Goel, N.; Habermann, T.; Hoischen, R.; Janik, R.; Karny, M.; Kaşkaş, A.; Kojouharov, I.; Kröll, Th.; Lewitowicz, M.; Litvinov, Yu.A.; Myalski, S.; Nebel, F.; Nishimura, S.; Nociforo, C.; Nyberg, J.; Parikh, A.; Procházka, A.; Regan, P.H.; Rigollet, C.; Schaffner, H.; Scheidenberger, C.; Schwertel, S.; Söderström, P.-A.; Steer, S.; Stolz, A.; Strmeň, P. in Physics Letters B (2021). 820 136591.
In a high-energy fragmentation experiment at GSI an I=π(6+) isomer and its γ-decay are identified in 102Sn, the two-neutron neighbour of the doubly-magic 100Sn. Its half-life is measured to be T=1/2367(11) ns. The possible existence of further isomers is discussed in the framework of large-scale shell model (LSSM) calculations including up to five particle-hole excitations of the 100Sn core. From the precise B(E2; 6+→4+) strength and the recently remeasured value for B(E2; 8+→6+) in the two-proton hole neighbour 98Cd effective E2 polarization charges for protons and neutrons were inferred including LSSM corrections within the full N=4 0ħω space. The results are discussed in comparison to predicted and empirically determined effective operators.
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Spectroscopy along Flerovium Decay Chains: Discovery of ²⁸⁰Ds and an Excited State in ²⁸²Cn. Såmark-Roth, A.; Cox, D. M.; Rudolph, D.; Sarmiento, L. G.; Carlsson, B. G.; Egido, J. L.; Golubev, P.; Heery, J.; Yakushev, A.; Åberg, S.; Albers, H. M.; Albertsson, M.; Block, M.; Brand, H.; Calverley, T.; Cantemir, R.; Clark, R. M.; Düllmann, Ch. E.; Eberth, J.; Fahlander, C.; Forsberg, U.; Gates, J. M.; Giacoppo, F.; Götz, M.; Götz, S.; Herzberg, R.-D.; Hrabar, Y.; Jäger, E.; Judson, D.; Khuyagbaatar, J.; Kindler, B.; Kojouharov, I.; Kratz, J. V.; Krier, J.; Kurz, N.; Lens, L.; Ljungberg, J.; Lommel, B.; Louko, J.; Meyer, C.-C.; Mistry, A.; Mokry, C.; Papadakis, P.; Parr, E.; Pore, J. L.; Ragnarsson, I.; Runke, J.; Schädel, M.; Schaffner, H.; Schausten, B.; Shaughnessy, D. A.; Thörle-Pospiech, P.; Trautmann, N.; Uusitalo, J. in Phys. Rev. Lett. (2021). 126(3) 032503.
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First beta-decay spectroscopy of 135In and new beta-decay branches of 134In. Piersa-Si\l{}kowska, M.; Korgul, A.; Benito, J.; Fraile, L. M.; Adamska, E.; Andreyev, A. N.; Álvarez-Rodr\'{i}guez, R.; Barzakh, A. E.; Benzoni, G.; Berry, T.; Borge, M. J. G.; Carmona, M.; Chrysalidis, K.; Correia, J. G.; Costache, C.; Cubiss, J. G.; Day Goodacre, T.; De Witte, H.; Fedorov, D. V.; Fedosseev, V. N.; Fernández-Mart\'{i}nez, G.; Fija\l{}kowska, A.; Fynbo, H.; Galaviz, D.; Galve, P.; Garc\'{\i}a-D\'{i}ez, M.; Greenlees, P. T.; Grzywacz, R.; Harkness-Brennan, L. J.; Henrich, C.; Huyse, M.; Ibá nez, P.; Illana, A.; Janas, Z.; Johnston, K.; Jolie, J.; Judson, D. S.; Karanyonchev, V.; Kiciifmmode \acute{n}else {{\'n}}\fi{}ska Habior, M.; Konki, J.; Koszuk, \L{}.; Kurcewicz, J.; Lazarus, I.; Licifmmode \u{a}else \u{a}\fi{}, R.; López-Montes, A.; Mach, H.; Madurga, M.; Marroqu\'{i}n, I.; Marsh, B.; Mart\'{i}nez, M. C.; Mazzocchi, C.; Miernik, K.; Mihai, C.; Mifmmode \u{a}else \u{a}\fi{}rginean, N.; Mifmmode \u{a}else \u{a}\fi{}rginean, R.; Negret, A.; Nácher, E.; Ojala, J.; Olaizola, B.; Page, R. D.; Pakarinen, J.; Pascu, S.; Paulauskas, S. V.; Perea, A.; Pucknell, V.; Rahkila, P.; Raison, C.; Rapisarda, E.; Rezynkina, K.; Rotaru, F.; Rothe, S.; Rykaczewski, K. P.; Régis, J.-M.; Schomacker, K.; Si\l{}kowski, M.; Simpson, G.; Sotty, C.; Stan, L.; Stifmmode \u{a}else \u{a}\fi{}noiu, M.; Stryjczyk, M.; Sánchez-Parcerisa, D.; Sánchez-Tembleque, V.; Tengblad, O.; Turturicifmmode \u{a}else \u{a}\fi{}, A.; Ud\'{i}as, J. M.; Van Duppen, P.; Vedia, V.; Villa, A.; Vi nals, S.; Wadsworth, R.; Walters, W. B.; Warr, N.; Wilkins, S. G. in Phys. Rev. C (2021). 104(4) 044328.
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First lifetime investigations of N > 82 iodine isotopes: The quest for collectivity. Häfner, G.; Lozeva, R.; Na\"{i}dja, H.; Lebois, M.; Jovancevic, N.; Thisse, D.; Etasse, D.; Canavan, R. L.; Rudigier, M.; Wilson, J. N.; Adamska, E.; Adsley, P.; Algora, A.; Babo, M.; Belvedere, K.; Benito, J.; Benzoni, G.; Blazhev, A.; Boso, A.; Bottoni, S.; Bunce, M.; Chakma, R.; Cieplicka-Oryifmmode \acute{n}else {{\'n}}\fi{}czak, N.; Collins, S. M.; Cortés, M. L.; Davies, P. J.; Delafosse, C.; Fallot, M.; Fraile, L. M.; Gerst, R.-B.; Gjestvang, D.; Guadilla, V.; Hauschild, K.; Henrich, C.; Homm, I.; Ibrahim, F.; Iskra, \L{}. W.; Jazwari, S.; Korgul, A.; Koseoglou, P.; Kröll, Th.; Kurtukian-Nieto, T.; Le meur, L.; Leoni, S.; Ljungvall, J.; Lopez-Martens, A.; Matthieu, L.; Miernik, K.; Nemer, J.; Oberstedt, S.; Paulsen, W.; Piersa-Si\l{}kowska, M.; Popovitch, Y.; Porzio, C.; Qi, L.; Ralet, D.; Regan, P. H.; Reygadas Tello, D.; Rezynkina, K.; Sanchez-Tembleque, V.; Schmitt, C.; Söderström, P.-A.; Sürder, C.; Tocabens, G.; Vedia, V.; Verney, D.; Warr, N.; Wasilewska, B.; Wiederhold, J.; Yavahchova, M. S.; Zeiser, F.; Ziliani, S. in Phys. Rev. C (2021). 104(1) 014316.
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New beta-decaying state in 214Bi. Andel, B.; Van Duppen, P.; Andreyev, A. N.; Blazhev, A.; Grawe, H.; Lica, R.; Naidja, H.; Stryjczyk, M.; Algora, A.; Antalic, S.; Barzakh, A.; Benito, J.; Benzoni, G.; Berry, T.; Borge, M. J. G.; Chrysalidis, K.; Clisu, C.; Costache, C.; Cubiss, J. G.; De Witte, H.; Fedorov, D. V.; Fedosseev, V. N.; Fraile, L. M.; Fynbo, H. O. U.; Greenlees, P. T.; Harkness-Brennan, L. J.; Huyse, M.; Illana, A.; Jolie, J.; Judson, D. S.; Konki, J.; Lazarus, I.; Madurga, M.; Marginean, N.; Marginean, R.; Mihai, C.; Marsh, B. A.; Molkanov, P.; Mosat, P.; Murias, J. R.; Nacher, E.; Negret, A.; Page, R. D.; Pascu, S.; Perea, A.; Pucknell, V.; Rahkila, P.; Rapisarda, E.; Rezynkina, K.; Sánchez-Tembleque, V.; Schomacker, K.; Seliverstov, M. D.; Sotty, C.; Stan, L.; Sürder, C.; Tengblad, O.; Vedia, V.; Vinals, S.; Wadsworth, R.; Warr, N. in Phys. Rev. C (2021). 104(5) 054301.
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Enhanced quadrupole collectivity in doubly-magic ⁵⁶Ni: Lifetime measurements of the 4₁⁺ and 6₁⁺ states. Arnswald, K.; Blazhev, A.; Nowacki, F.; Petkov, P.; Reiter, P.; Braunroth, T.; Dewald, A.; Droste, M.; Fransen, C.; Hirsch, R.; Karayonchev, V.; Kaya, L.; Lewandowski, L.; Müller-Gatermann, C.; Seidlitz, M.; Siebeck, B.; Vogt, A.; Werner, D.; Zell, K.O. in Phys. Lett. B (2021). 820 136592.
Lifetime measurements of excited states in doubly-magic 56Ni have been performed exploiting the Doppler-shift attenuation method in order to determine reduced transition probabilities. For the 41+ and 61+ states, the deduced B(E2) values are compared with results from shell-model calculations employing the GXPF1A and the modern PFSDG-U interactions. In addition, valence ab-initio calculations were performed using a novel realistic Hamiltonian derived from chiral perturbation theory including three-body potential contributions and are confronted with the experimental findings. The new results show maximum E2 strength in comparison with known values along the N=28 chain of isotones. The results corroborate the high collectivity for the double shell closure at N=Z=28 which was anticipated from the large B(E2;21+→0g.s.+) value despite the considerable increase of its excitation energy as compared to neighboring semi-magic nuclei. Based on similarities in the shell structures of the self-conjugate doubly-magic nuclei 56Ni and 100Sn, the new values could be an indication for an expected comparable collective behavior of the 61+ state in 100Sn.
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Lifetime measurements of excited states in ⁵⁵Cr. Kleis, H.; Seidlitz, M.; Blazhev, A.; Kaya, L.; Reiter, P.; Arnswald, K.; Dewald, A.; Droste, M.; Fransen, C.; Möller, O.; Shimizu, N.; Tsunoda, Y.; Utsuno, Y.; von Brentano, P.; Zell, K. O. in Phys. Rev. C (2021). 104(3) 034310.
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Spectroscopy and lifetime measurements in ¹³⁴,¹³⁶,¹³⁸Te isotopes and implications for the nuclear structure beyond N=82. Häfner, G.; Lozeva, R.; Naidja, H.; Lebois, M.; Jovancevic, N.; Thisse, D.; Etasse, D.; Canavan, R. L.; Rudigier, M.; Wilson, J. N.; Adamska, E.; Adsley, P.; Babo, M.; Belvedere, K.; Benito, J.; Benzoni, G.; Blazhev, A.; Boso, A.; Bottoni, S.; Bunce, M.; Chakma, R.; Cieplicka-Orynczak, N.; Collins, S. M.; Cortés, M. L.; Davies, P. J.; Delafosse, C.; Fallot, M.; Fornal, B.; Fraile, L. M.; Gerst, R.-B.; Gjestvang, D.; Guadilla, V.; Hauschild, K.; Henrich, C.; Homm, I.; Ibrahim, F.; Iskra, L. W.; Jazwari, S.; Jolie, J.; Korgul, A.; Koseoglou, P.; Kröll, Th.; Kurtukian-Nieto, T.; Le meur, L.; Ljungvall, J.; Lopez-Martens, A.; Matea, I.; Matthieu, L.; Miernik, K.; Nemer, J.; Oberstedt, S.; Paulsen, W.; Piersa, M.; Popovitch, Y.; Porzio, C.; Qi, L.; Ralet, D.; Regan, P. H.; Reygadas Tello, D.; Rezynkina, K.; Sanchez, V.; Schmitt, C.; Söderström, P.-A.; Sürder, C.; Tocabens, G.; Vedia, V.; Verney, D.; Warr, N.; Wasilewska, B.; Wiederhold, J.; Yavahchova, M. S.; Zeiser, F.; Ziliani, S. in Phys. Rev. C (2021). 103(3) 034317.
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Lifetimes and structures of low-lying negative-parity states of 209Po. Karayonchev, V.; Stoyanova, M.; Rainovski, G.; Jolie, J.; Blazhev, A.; Djongolov, M.; Esmaylzadeh, A.; Fransen, C.; Gladnishki, K.; Knafla, L.; Kocheva, D.; Kornwebel, L.; Régis, J.-M.; De Gregorio, G.; Gargano, A. in Phys. Rev. C (2021). 103(4) 044309.
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Angular momentum generation in nuclear fission. Wilson, J. N.; Thisse, D.; Lebois, M.; Jovančević, N.; Gjestvang, D.; Canavan, R.; Rudigier, M.; Étasse, D.; Gerst, R-B; Gaudefroy, L.; Adamska, E.; Adsley, P.; Algora, A.; Babo, M.; Belvedere, K.; Benito, J.; Benzoni, G.; Blazhev, A.; Boso, A.; Bottoni, S.; Bunce, M.; Chakma, R.; Cieplicka-Oryńczak, N.; Courtin, S.; Cortés, M. L.; Davies, P.; Delafosse, C.; Fallot, M.; Fornal, B.; Fraile, L.; Gottardo, A.; Guadilla, V.; Häfner, G.; Hauschild, K.; Heine, M.; Henrich, C.; Homm, I.; Ibrahim, F.; Iskra, Ł. W.; Ivanov, P.; Jazrawi, S.; Korgul, A.; Koseoglou, P.; Kröll, T.; Kurtukian-Nieto, T.; Le Meur, L.; Leoni, S.; Ljungvall, J.; Lopez-Martens, A.; Lozeva, R.; Matea, I.; Miernik, K.; Nemer, J.; Oberstedt, S.; Paulsen, W.; Piersa, M.; Popovitch, Y.; Porzio, C.; Qi, L.; Ralet, D.; Regan, P. H.; Rezynkina, K.; Sánchez-Tembleque, V.; Siem, S.; Schmitt, C.; Söderström, P.-A; Sürder, C.; Tocabens, G.; Vedia, V.; Verney, D.; Warr, N.; Wasilewska, B.; Wiederhold, J.; Yavahchova, M.; Zeiser, F.; Ziliani, S. in Nature (2021). 590(7847) 566--570.
When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning1; this phenomenon has been a mystery in nuclear physics for over 40 years2,3. The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum4–12. Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the γ-ray heating problem in nuclear reactors13,14, for the study of the structure of neutron-rich isotopes15,16, and for the synthesis and stability of super-heavy elements17,18.
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Evidence for enhanced neutron-proton correlations from the level structure of the N=Z+1 nucleus ₄₃⁸⁷Tc₄₄. Liu, X.; Cederwall, B.; Qi, C.; Wyss, R. A.; Aktas, Ö.; Ertoprak, A.; Zhang, W.; Clément, E.; de France, G.; Ralet, D.; Gadea, A.; Goasduff, A.; Jaworski, G.; Kuti, I.; Nyakó, B. M.; Nyberg, J.; Palacz, M.; Wadsworth, R.; Valiente-Dobón, J. J.; Al-Azri, H.; Ataç Nyberg, A.; Bäck, T.; de Angelis, G.; Doncel, M.; Dudouet, J.; Gottardo, A.; Jurado, M.; Ljungvall, J.; Mengoni, D.; Napoli, D. R.; Petrache, C. M.; Sohler, D.; Timár, J.; Barrientos, D.; Bednarczyk, P.; Benzoni, G.; Birkenbach, B.; Boston, A. J.; Boston, H. C.; Burrows, I.; Charles, L.; Ciemala, M.; Crespi, F. C. L.; Cullen, D. M.; Désesquelles, P.; Domingo-Pardo, C.; Eberth, J.; Erduran, N.; Ertürk, S.; González, V.; Goupil, J.; Hess, H.; Huyuk, T.; Jungclaus, A.; Korten, W.; Lemasson, A.; Leoni, S.; Maj, A.; Menegazzo, R.; Million, B.; Perez-Vidal, R. M.; Podolyàk, Zs.; Pullia, A.; Recchia, F.; Reiter, P.; Saillant, F.; Salsac, M. D.; Sanchis, E.; Simpson, J.; Stezowski, O.; Theisen, C.; Zielińska, M. in Phys. Rev. C (2021). 104(2) L021302.
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Nuclear structure studies with re-accelerated beams at REX-and HIE-ISOLDE. Reiter, P.; Warr, N. in Progress in Particle and Nuclear Physics (2020). 113 103767.
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Prompt and delayed gamma spectroscopy of neutron-rich 94Kr and observation of a new isomer. Gerst, R.-B.; Blazhev, A.; Warr, N.; Wilson, J. N.; Lebois, M.; Jovančević, N.; Thisse, D.; Canavan, R.; Rudigier, M.; Étasse, D.; Adamska, E.; Adsley, P.; Algora, A.; Babo, M.; Belvedere, K.; Benito, J.; Benzoni, G.; Boso, A.; Bottoni, S.; Bunce, M.; Chakma, R.; Cieplicka-Oryńczak, N.; Courtin, S.; Cortés, M. L.; Davies, P.; Delafosse, C.; Fallot, M.; Fornal, B.; Fraile, L. M.; Gjestvang, D.; Gottardo, A.; Guadilla, V.; Häfner, G.; Hauschild, K.; Heine, M.; Henrich, C.; Homm, I.; Ibrahim, F.; Iskra, L. W.; Ivanov, P.; Jazrawi, S.; Korgul, A.; Koseoglou, P.; Kröll, T.; Kurtukian-Nieto, T.; Le Meur, L.; Leoni, S.; Ljungvall, J.; Lopez-Martens, A.; Lozeva, R.; Matea, I.; Miernik, K.; Nemer, J.; Oberstedt, S.; Paulsen, W.; Piersa, M.; Popovitch, Y.; Porzio, C.; Qi, L.; Ralet, D.; Regan, P. H.; Reygadas-Tello, D.; Rezynkina, K.; Sánchez-Tembleque, V.; Schmitt, C.; Söderström, P.-A.; Sürder, C.; Tocabens, G.; Vedia, V.; Verney, D.; Wasilewska, B.; Wiederhold, J.; Yavachova, M.; Zeiser, F.; Ziliani, S. in Phys. Rev. C (2020). 102(6) 064323.
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Fast-timing study of 81Ga from the β decay of 81Zn. Paziy, V.; Fraile, L. M.; Mach, H.; Olaizola, B.; Simpson, G. S.; Aprahamian, A.; Bernards, C.; Briz, J. A.; Bucher, B.; Chiara, C. J.; Dlouhý, Z.; Gheorghe, I.; Ghiţǎ, D.; Hoff, P.; Jolie, J.; Köster, U.; Kurcewicz, W.; Licǎ, R.; Mǎrginean, N.; Mǎrginean, R.; Régis, J. M.; Rudigier, M.; Sava, T.; Stǎnoiu, M.; Stroe, L.; Walters, W. B. in Phys. Rev. C (2020). 102(1) 014329.
The β− decay of 81Zn to the neutron magic N = 50 nucleus 81Ga, with only three valence protons with respect to 78Ni, was investigated. The study was performed at the ISOLDE facility at CERN by means of γ spectroscopy. The 81Zn half-life was determined to be T1/2 = 290(4) ms while the β-delayed neutron emission probability was measured as Pn = 23(4)%. The analysis of the β-gated γ -ray singles and γ -γ coincidences from the decay of 81Zn provides 47 new levels and 70 new transitions in 81Ga. The β−n decay of 81Zn was observed and a new decay scheme into the odd-odd 80Ga nucleus was established. The half-lives of the first and second excited states of 81Ga were measured via the fast-timing method using LaBr3(Ce) detectors. The level scheme and transition rates are compared to large-scale shell-model calculations. The low-lying structure of 81Ga is interpreted in terms of the coupling of the three valence protons outside the doubly magic 78Ni core.
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Sequential Nature of \($(p,3p)$\) Two-Proton Knockout from Neutron-Rich Nuclei. Frotscher, A.; Gómez-Ramos, M.; Obertelli, A.; Doornenbal, P.; Authelet, G.; Baba, H.; Calvet, D.; Château, F.; Chen, S.; Corsi, A.; Delbart, A.; Gheller, J.-M.; Giganon, A.; Gillibert, A.; Isobe, T.; Lapoux, V.; Matsushita, M.; Momiyama, S.; Motobayashi, T.; Niikura, M.; Otsu, H.; Paul, N.; Péron, C.; Peyaud, A.; Pollacco, E. C.; Roussé, J.-Y.; Sakurai, H.; Santamaria, C.; Sasano, M.; Shiga, Y.; Shimizu, N.; Steppenbeck, D.; Takeuchi, S.; Taniuchi, R.; Uesaka, T.; Wang, H.; Yoneda, K.; Ando, T.; Arici, T.; Blazhev, A.; Browne, F.; Bruce, A. M.; Carroll, R.; Chung, L. X.; Cortés, M. L.; Dewald, M.; Ding, B.; Dombradi, Zs.; Flavigny, F.; Franchoo, S.; Giacoppo, F.; Górska, M.; Gottardo, A.; Hadyifmmode \acute{n}else {{\'n}}\fi{}ska-Klifmmode \mbox{\k{e}}else \k{e}\fi{}k, K.; Korkulu, Z.; Koyama, S.; Kubota, Y.; Jungclaus, A.; Lee, J.; Lettmann, M.; Linh, B. D.; Liu, J.; Liu, Z.; Lizarazo, C.; Louchart, C.; Lozeva, R.; Matsui, K.; Miyazaki, T.; Moschner, K.; Nagamine, S.; Nakatsuka, N.; Nita, C.; Nishimura, S.; Nobs, C. R.; Olivier, L.; Ota, S.; Patel, Z.; Podolyák, Zs.; Rudigier, M.; Sahin, E.; Saito, T. Y.; Shand, C.; Söderström, P.-A.; Stefan, I. G.; Sumikama, T.; Suzuki, D.; Orlandi, R.; Vaquero, V.; Vajta, Zs.; Werner, V.; Wimmer, K.; Wu, J.; Xu, Z. in Phys. Rev. Lett. (2020). 125(1) 012501.
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FATIMA — FAst TIMing Array for DESPEC at FAIR. Rudigier, M.; Podolyák, Zs.; Regan, P.H.; Bruce, A.M.; Lalkovski, S.; Canavan, R.L.; Gamba, E.R.; Roberts, O.; Burrows, I.; Cullen, D.M.; Fraile, L.M.; Gerhard, L.; Gerl, J.; Gorska, M.; Grant, A.; Jolie, J.; Karayonchev, V.; Kurz, N.; Korten, W.; Lazarus, I.H.; Nita, C.R.; Pucknell, V.F.E.; Régis, J.-M.; Schaffner, H.; Simpson, J.; Singh, P.; Townsley, C.M.; Smith, J.F.; Vesic, J. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2020). 969 163967.
The components, working principle and characteristics of FATIMA (FAst TIMing Array), a fast-timing detector system for DESPEC at FAIR, are described. The core system includes 36 LaBr3(Ce) scintillator detectors, a mounting frame for the DESPEC station and a VME-based fast-timing data acquisition system. The current electronic timing circuit is based on V812 constant fraction discriminators and V1290 time-to-digital converters. Gamma-ray energies are measured using V1751 digitisers. Characteristics of the core FATIMA system including efficiency, energy, and coincidence resolving time, as well as limitations, are discussed on the basis of test measurements performed in the S4 cave at GSI, Germany. The coincidence γ-γ time resolution for the prompt 60Co cascade is determined to be ∼320 ps full width at half maximum. The total full energy peak efficiency at 1 MeV for the 36 detector array in the DESPEC setup is 2.9%. The energy-dependent prompt response centroid curve with the current CFD/TDC combination is shown to be smooth; the centroid shift method can be applied for the measurement of half-lives below 200 ps. An overview of applications of the FATIMA detectors as an ancilliary system in combination with other detector arrays during recent years is given. Data on the operation of the detectors in the presence of magnetic fields are presented.
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Isospin Properties of Nuclear Pair Correlations from the Level Structure of the Self-Conjugate Nucleus ⁸⁸Ru. Cederwall, B.; Liu, X.; Aktas, Ö.; Ertoprak, A.; Zhang, W.; Qi, C.; Clément, E.; de France, G.; Ralet, D.; Gadea, A.; Goasduff, A.; Jaworski, G.; Kuti, I.; Nyakó, B. M.; Nyberg, J.; Palacz, M.; Wadsworth, R.; Valiente-Dobón, J. J.; Al-Azri, H.; Ataç Nyberg, A.; Bäck, T.; de Angelis, G.; Doncel, M.; Dudouet, J.; Gottardo, A.; Jurado, M.; Ljungvall, J.; Mengoni, D.; Napoli, D. R.; Petrache, C. M.; Sohler, D.; Timár, J.; Barrientos, D.; Bednarczyk, P.; Benzoni, G.; Birkenbach, B.; Boston, A. J.; Boston, H. C.; Burrows, I.; Charles, L.; Ciemala, M.; Crespi, F. C. L.; Cullen, D. M.; Désesquelles, P.; Domingo-Pardo, C.; Eberth, J.; Erduran, N.; Ertürk, S.; González, V.; Goupil, J.; Hess, H.; Huyuk, T.; Jungclaus, A.; Korten, W.; Lemasson, A.; Leoni, S.; Maj, A.; Menegazzo, R.; Million, B.; Perez-Vidal, R. M.; Podolyak, Zs.; Pullia, A.; Recchia, F.; Reiter, P.; Saillant, F.; Salsac, M. D.; Sanchis, E.; Simpson, J.; Stezowski, O.; Theisen, Ch.; Zielińska, M. in Phys. Rev. Lett. (2020). 124(6) 062501.
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Testing ab initio nuclear structure in neutron-rich nuclei: Lifetime measurements of second 2⁺ state in ¹⁶C and ²⁰O. Ciemała, M.; Ziliani, S.; Crespi, F. C. L.; Leoni, S.; Fornal, B.; Maj, A.; Bednarczyk, P.; Benzoni, G.; Bracco, A.; Boiano, C.; Bottoni, S.; Brambilla, S.; Bast, M.; Beckers, M.; Braunroth, T.; Camera, F.; Cieplicka-Oryńczak, N.; Clément, E.; Coelli, S.; Dorvaux, O.; Erturk, S.; de France, G.; Fransen, C.; Goldkuhle, A.; Grębosz, J.; Harakeh, M. N.; Iskra, Ł. W.; Jacquot, B.; Karpov, A.; Kicińska Habior, M.; Kim, Y.; Kmiecik, M.; Lemasson, A.; Lenzi, S. M.; Lewitowicz, M.; Li, H.; Matea, I.; Mazurek, K.; Michelagnoli, C.; Matejska-Minda, M.; Million, B.; Müller-Gatermann, C.; Nanal, V.; Napiorkowski, P.; Napoli, D. R.; Palit, R.; Rejmund, M.; Schmitt, Ch.; Stanoiu, M.; Stefan, I.; Vardaci, E.; Wasilewska, B.; Wieland, O.; Zieblinski, M.; Zielińska, M.; Ataç, A.; Barrientos, D.; Birkenbach, B.; Boston, A. J.; Cederwall, B.; Charles, L.; Collado, J.; Cullen, D. M.; Désesquelles, P.; Domingo-Pardo, C.; Dudouet, J.; Eberth, J.; González, V.; Goupil, J.; Harkness-Brennan, L. J.; Hess, H.; Judson, D. S.; Jungclaus, A.; Korten, W.; Labiche, M.; Lefevre, A.; Menegazzo, R.; Mengoni, D.; Nyberg, J.; Perez-Vidal, R. M.; Podolyak, Zs.; Pullia, A.; Recchia, F.; Reiter, P.; Saillant, F.; Salsac, M. D.; Sanchis, E.; Stezowski, O.; Theisen, Ch.; Valiente-Dobón, J. J.; Holt, J. D.; Menéndez, J.; Schwenk, A.; Simonis, J. in Phys. Rev. C (2020). 101(2) 021303.
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Quadrupole deformation of 130Xe measured in a Coulomb-excitation experiment. Morrison, L.; Hadyńska-Klȩk, K.; Podolyák, Zs.; Doherty, D. T.; Gaffney, L. P.; Kaya, L.; Próchniak, L.; Samorajczyk-Pyśk, J.; Srebrny, J.; Berry, T.; Boukhari, A.; Brunet, M.; Canavan, R.; Catherall, R.; Colosimo, S. J.; Cubiss, J. G.; De Witte, H.; Fransen, Ch.; Giannopoulos, E.; Hess, H.; Kröll, T.; Lalović, N.; Marsh, B.; Palenzuela, Y. Martinez; Napiorkowski, P. J.; O'Neill, G.; Pakarinen, J.; Ramos, J. P.; Reiter, P.; Rodriguez, J. A.; Rosiak, D.; Rothe, S.; Rudigier, M.; Siciliano, M.; Snäll, J.; Spagnoletti, P.; Thiel, S.; Warr, N.; Wenander, F.; Zidarova, R.; Zielińska, M. in Phys. Rev. C (2020). 102(5) 054304.
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Evolution of collectivity in 118Xe. Müller-Gatermann, C.; Dewald, A.; Fransen, C.; Beckers, M.; Blazhev, A.; Braunroth, T.; Goldkuhle, A.; Jolie, J.; Kornwebel, L.; Reviol, W.; von Spee, F.; Zell, K. O. in Phys. Rev. C (2020). 102(6) 064318.
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Low-lying electric dipole γ-continuum for the unstable 62,64Fe nuclei: Strength evolution with neutron number. Avigo, R.; Wieland, O.; Bracco, A.; Camera, F.; Ameil, F.; Arici, T.; Ataç, A.; Barrientos, D.; Bazzacco, D.; Bednarczyk, P.; Benzoni, G.; Birkenbach, B.; Blasi, N.; Boston, H.C.; Bottoni, S.; Brambilla, S.; Bruyneel, B.; Ciemała, M.; Clément, E.; Cortés, M.L.; Crespi, F.C.L.; Cullen, D.M.; Curien, D.; Didierjean, F.; Domingo-Pardo, C.; Duchêne, G.; Eberth, J.; Görgen, A.; Gadea, A.; Gerl, J.; Goel, N.; Golubev, P.; González, V.; Górska, M.; Gottardo, A.; Gregor, E.; Guastalla, G.; Habermann, T.; Harkness-Brennan, L.J.; Jungclaus, A.; Kmiecik, M.; Kojouharov, I.; Korten, W.; Kurz, N.; Labiche, M.; Lalović, N.; Leoni, S.; Lettmann, M.; Maj, A.; Menegazzo, R.; Mengoni, D.; Merchan, E.; Million, B.; Morales, A.I.; Napoli, D.R.; Nociforo, C.; Nyberg, J.; Pietralla, N.; Pietri, S.; Podolyák, Zs.; Ponomarev, V.Yu.; Pullia, A.; Quintana, B.; Rainovski, G.; Ralet, D.; Recchia, F.; Reese, M.; Regan, P.; Reiter, P.; Riboldi, S.; Rudolph, D.; Salsac, M.D.; Sanchis, E.; Sarmiento, L.G.; Schaffner, H.; Simpson, J.; Stezowski, O.; Valiente-Dobón, J.J.; Wollersheim, H.J. in Physics Letters B (2020). 811 135951.
The γ-ray emission from the nuclei 62,64Fe following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei 62,64Fe were produced at the FAIR-GSI laboratories and selected with the FRS spectrometer. The γ decay was detected with AGATA. From the measured γ-ray spectra the summed E1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1− states (three-phonon states) inducing a strong fragmentation of the E1 nuclear response below the neutron binding energy.
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Tests of collectivity in 98Zr by absolute transition rates. Karayonchev, V.; Jolie, J.; Blazhev, A.; Dewald, A.; Esmaylzadeh, A.; Fransen, C.; Häfner, G.; Knafla, L.; Litzinger, J.; Müller-Gatermann, C.; Régis, J.-M.; Schomacker, K.; Vogt, A.; Warr, N.; Leviatan, A.; Gavrielov, N. in Phys. Rev. C (2020). 102(6) 064314.
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Lifetime measurements of excited states in neutron-rich 53Ti: Benchmarking effective shell-model interactions. Goldkuhle, A.; Blazhev, A.; Fransen, C.; Dewald, A.; Beckers, M.; Birkenbach, B.; Braunroth, T.; Clément, E.; Dudouet, J.; Eberth, J.; Hess, H.; Jacquot, B.; Jolie, J.; Kim, Y.-H.; Lemasson, A.; Lenzi, S. M.; Li, H. J.; Litzinger, J.; Michelagnoli, C.; Müller-Gatermann, C.; Nara Singh, B. S.; Pérez-Vidal, R. M.; Ralet, D.; Reiter, P.; Vogt, A.; Warr, N.; Zell, K. O. in Phys. Rev. C (2020). 102(5) 054334.
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Lifetime measurements in ⁴⁴Ti. Arnswald, K.; Reiter, P.; Blazhev, A.; Braunroth, T.; Dewald, A.; Droste, M.; Fransen, C.; Goldkuhle, A.; Hetzenegger, R.; Hirsch, R.; Hoemann, E.; Kaya, L.; Lewandowski, L.; Müller-Gatermann, C.; Petkov, P.; Rosiak, D.; Seidlitz, M.; Siebeck, B.; Vogt, A.; Werner, D.; Wolf, K.; Zell, K.-O. in Phys. Rev. C (2020). 102(5) 054302.
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Lifetime measurements of 162Er: Evolution of collectivity in the rare-earth region. Knafla, L.; Häfner, G.; Jolie, J.; Régis, J.-M.; Karayonchev, V.; Blazhev, A.; Esmaylzadeh, A.; Fransen, C.; Goldkuhle, A.; Herb, S.; Müller-Gatermann, C.; Warr, N.; Zell, K. O. in Phys. Rev. C (2020). 102(4) 044310.
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Restoring the valence-shell stabilization in 140Nd. Kern, R.; Zidarova, R.; Pietralla, N.; Rainovski, G.; Stegmann, R.; Blazhev, A.; Boukhari, A.; Cederkäll, J.; Cubiss, J. G.; Djongolov, M.; Fransen, C.; Gaffney, L. P.; Gladnishki, K.; Giannopoulos, E.; Hess, H.; Jolie, J.; Karayonchev, V.; Kaya, L.; Keatings, J. M.; Kocheva, D.; Kröll, Th.; Möller, O.; O'Neill, G. G.; Pakarinen, J.; Reiter, P.; Rosiak, D.; Scheck, M.; Snall, J.; Söderström, P.-A.; Spagnoletti, P.; Stoyanova, M.; Thiel, S.; Vogt, A.; Warr, N.; Welker, A.; Werner, V.; Wiederhold, J.; De Witte, H. in Phys. Rev. C (2020). 102(4) 041304.
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Population of lead isotopes in binary reactions using a 94Rb radioactive beam. Čolović, P.; Szilner, S.; Illana, A.; Valiente-Dobón, J. J.; Corradi, L.; Pollarolo, G.; Mijatović, T.; Goasduff, A.; Benzoni, G.; Borge, M. J. G.; Boso, A.; Boukhari, A.; Ceruti, S.; Cubiss, J. G.; de Angelis, G.; De Witte, H.; Fioretto, E.; Fransen, Ch.; Galtarossa, F.; Gaffney, L. P.; Giannopoulos, E.; Hess, H.; Jurado-Gomez, M. L.; Kaya, L.; Kröll, Th.; Marchi, T.; Menegazzo, R.; Mengoni, D.; Napoli, D. R.; O'Neill, G.; Pakarinen, J.; Podolyák, Zs.; Recchia, F.; Reiter, P.; Rosiak, D.; Snall, J.; Spagnoletti, P.; Testov, D.; Thiel, S.; Warr, N.; Zidarova, R. in Phys. Rev. C (2020). 102(5) 054609.
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New measurement of the 144Sm(alpha,gamma)148Gd reaction rate for the gamma process. Scholz, P.; Wilsenach, H.; Becker, H. W.; Blazhev, A.; Heim, F.; Foteinou, V.; Giesen, U.; Münker, C.; Rogalla, D.; Sprung, P.; Zilges, A.; Zuber, K. in Phys. Rev. C (2020). 102(4) 045811.
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Competition between Allowed and First-Forbidden Beta Decay: The Case of 208Hg -> 208Tl. Carroll, R. J.; Podolyák, Zs.; Berry, T.; Grawe, H.; Alexander, T.; Andreyev, A. N.; Ansari, S.; Borge, M. J. G.; Brunet, M.; Creswell, J. R.; Fraile, L. M.; Fahlander, C.; Fynbo, H. O. U.; Gamba, E. R.; Gelletly, W.; Gerst, R.-B.; Górska, M.; Gredley, A.; Greenlees, P. T.; Harkness-Brennan, L. J.; Huyse, M.; Judge, S. M.; Judson, D. S.; Konki, J.; Kurcewicz, J.; Kuti, I.; Lalkovski, S.; Lazarus, I. H.; Licifmmode \u{a}else \u{a}\fi{}, R.; Lund, M.; Madurga, M.; Marginean, N.; Marginean, R.; Marroquin, I.; Mihai, C.; Mihai, R. E.; Nácher, E.; Negret, A.; Nita, C.; Pascu, S.; Page, R. D.; Patel, Z.; Perea, A.; Phrompao, J.; Piersa, M.; Pucknell, V.; Rahkila, P.; Rapisarda, E.; Regan, P. H.; Rotaru, F.; Rudigier, M.; Shand, C. M.; Shearman, R.; Stegemann, S.; Stora, T.; Sotty, Ch.; Tengblad, O.; Van Duppen, P.; Vedia, V.; Wadsworth, R.; Walker, P. M.; Warr, N.; Wearing, F.; De Witte, H. in Phys. Rev. Lett. (2020). 125(19) 192501.
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Quadrupole deformation of 130Xe measured in a Coulomb-excitation experiment. Morrison, L.; Hadyńska-Klek, K.; Podolyák, Zs.; Doherty, D. T.; Gaffney, L. P.; Kaya, L.; Próchniak, L.; Samorajczyk-Pyśk, J.; Srebrny, J.; Berry, T.; Boukhari, A.; Brunet, M.; Canavan, R.; Catherall, R.; Colosimo, S. J.; Cubiss, J. G.; De Witte, H.; Fransen, Ch.; Giannopoulos, E.; Hess, H.; Kröll, T.; Lalovic, N.; Marsh, B.; Palenzuela, Y. Martinez; Napiorkowski, P. J.; O'Neill, G.; Pakarinen, J.; Ramos, J. P.; Reiter, P.; Rodriguez, J. A.; Rosiak, D.; Rothe, S.; Rudigier, M.; Siciliano, M.; Snäll, J.; Spagnoletti, P.; Thiel, S.; Warr, N.; Wenander, F.; Zidarova, R.; Zielińska, M. in Phys. Rev. C (2020). 102(5) 054304.
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Experimental evidence for low-lying quadrupole isovector excitation of 208Po. Yaneva, A.; Kocheva, D.; Rainovski, G.; Jolie, J.; Pietralla, N.; Blazhev, A.; Dewald, A.; Djongolov, M.; Fransen, C.; Gladnishki, K. A.; Henrich, C.; Homm, I.; Ide, K. E.; John, P. R.; Kalaydjieva, D.; Karayonchev, V.; Kern, R.; Kleemann, J.; Kröll, Th.; Müller-Gatermann, C.; Scheck, M.; Spagnoletti, P.; Stoyanova, M.; Werner, V. in The European Physical Journal A (2020). 56(246) 7.
We present the results from an experiment dedicated to measure the lifetime of the 22+ state, candidate for the one-phonon mixed-symmetry state, of 208Po. This nucleus was studied in the α-transfer reaction 204Pb(12C,8Be)208Po and the lifetime of the 22+ state was determined by utilizing the Doppler-shift attenuation method. The experimental data show that the 22+ state decays with a sizable M1 transition to the 21+ state revealing its isovector nature.
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Decay studies of the long-lived states in \($^{186}\mathrm{Tl}$\). Stryjczyk, M.; Andel, B.; Andreyev, A. N.; Cubiss, J.; Pakarinen, J.; Rezynkina, K.; Van Duppen, P.; Antalic, S.; Berry, T.; Borge, M. J. G.; Clisu, C.; Cox, D. M.; De Witte, H.; Fraile, L. M.; Fynbo, H. O. U.; Gaffney, L. P.; Harkness-Brennan, L. J.; Huyse, M.; Illana, A.; Judson, D. S.; Konki, J.; Kurcewicz, J.; Lazarus, I.; Lica, R.; Madurga, M.; Marginean, N.; Marginean, R.; Mihai, C.; Mosat, P.; Nacher, E.; Negret, A.; Ojala, J.; Ovejas, J. D.; Page, R. D.; Papadakis, P.; Pascu, S.; Perea, A.; Podolyák, Zs.; Pucknell, V.; Rapisarda, E.; Rotaru, F.; Sotty, C.; Tengblad, O.; Vedia, V.; Vi nals, S.; Wadsworth, R.; Warr, N.; Wrzosek-Lipska, K. in Phys. Rev. C (2020). 102(2) 024322.
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Studying the Exotic Decay 70Kr to 70Br. Vitéz-Sveiczer, A.; Algora, A.; Morales, A.I.; Rubio, B.; Kiss, G.G.; de Angelis, G.; Recchia, F.; Nishimura, S.; Agramunt, J.; Guadilla, V.; Montaner-Pizá, A.; Orrigo, S.E.A.; Horváth, A.; Napoli, D.; Lenzi, S.; Boso, A.; Phong, V.H.; Wu, J.; Söderström, P.-A.; Sumikama, T.; Suzuki, H.; Takeda, H.; Ahn, D.S.; Baba, H.; Doornenbal, P.; Fukuda, N.; Inabe, N.; Isobe, T.; Kubo, T.; Kubono, S.; Sakurai, H.; Shimizu, Y.; Chen, S.; Blank, B.; Ascher, P.; Gerbaux, M.; Goigoux, T.; Giovinazzo, J.; Grévy, S.; Kurtukián Nieto, T.; Magron, C.; Gelletly, W.; Dombrádi, Zs.; Fujita, Y.; Tanaka, M.; Aguilera, P.; Molina, F.; Eberth, J.; Diel, F.; Lubos, D.; Borcea, C.; Ganioglu, E.; Nishimura, D.; Oikawa, H.; Takei, Y.; Yagi, S.; Korten, W.; de France, G.; Davies, P.; Liu, J.; Lee, J.; Lokotko, T.; Kojouharov, I.; Kurz, N.; Shaffner, H. in Acta Physica Polonica B (2020). 51(3) 587-594.
Beta-decay of the very neutron-deficient Kr isotope, 70Kr, was studied at RIKEN-RIBF using the EURICA cluster array. The experiment significantly increased our knowledge of the beta-decay of this isotope. Namely, 16 new γ-ray transitions were identified and the half-life was derived from time correlations of the beta particles (tiβ1/2=(44.99±0.16) ms) and from the decay curves of the observed γ-ray transitions (tiβγ1/2=(45.16±0.71) ms), respectively.
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Half-life measurements in \($^{164,166}\mathrm{Dy}$\) using \($\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$\) fast-timing spectroscopy with the \($\ensuremath{\nu}$\)-Ball spectrometer. Canavan, R. L.; Rudigier, M.; Regan, P. H.; Lebois, M.; Wilson, J. N.; Jovancevic, N.; Söderström, P.-A.; Collins, S. M.; Thisse, D.; Benito, J.; Bottoni, S.; Brunet, M.; Cieplicka-Orynczak, N.; Courtin, S.; Doherty, D. T.; Fraile, L. M.; Hadynska-Klek, K.; Häfner, G.; Heine, M.; Iskra, \L{}. W.; Karayonchev, V.; Kennington, A.; Koseoglou, P.; Lotay, G.; Lorusso, G.; Nakhostin, M.; Nita, C. R.; Oberstedt, S.; Podolyák, Zs.; Qi, L.; Régis, J.-M.; Sánchez-Tembleque, V.; Shearman, R.; Vedia, V.; Witt, W. in Phys. Rev. C (2020). 101(2) 024313.
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Metastable States of 92,94Se: Identification of an Oblate K Isomer of 94Se and the Ground-State Shape Transition between N=58 and 60. Lizarazo, C.; Söderström, P.-A.; Werner, V.; Pietralla, N.; Walker, P. M.; Dong, G. X.; Xu, F. R.; Rodr\'{i}guez, T. R.; Browne, F.; Doornenbal, P.; Nishimura, S.; Niifmmode \mbox{\c{t}}else \c{t}\fi{}ifmmode \u{a}else \u{a}\fi{}, C. R.; Obertelli, A.; Ando, T.; Arici, T.; Authelet, G.; Baba, H.; Blazhev, A.; Bruce, A. M.; Calvet, D.; Caroll, R. J.; Château, F.; Chen, S.; Chung, L. X.; Corsi, A.; Cortés, M. L.; Delbart, A.; Dewald, M.; Ding, B.; Flavigny, F.; Franchoo, S.; Gerl, J.; Gheller, J.-M.; Giganon, A.; Gillibert, A.; Górska, M.; Gottardo, A.; Kojouharov, I.; Kurz, N.; Lapoux, V.; Lee, J.; Lettmann, M.; Linh, B. D.; Liu, J. J.; Liu, Z.; Momiyama, S.; Moschner, K.; Motobayashi, T.; Nagamine, S.; Nakatsuka, N.; Niikura, M.; Nobs, C.; Olivier, L.; Patel, Z.; Paul, N.; Podolyák, Zs.; Roussé, J.-Y.; Rudigier, M.; Saito, T. Y.; Sakurai, H.; Santamaria, C.; Schaffner, H.; Shand, C.; Stefan, I.; Steppenbeck, D.; Taniuchi, R.; Uesaka, T.; Vaquero, V.; Wimmer, K.; Xu, Z. in Phys. Rev. Lett. (2020). 124(22) 222501.
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Physics opportunities with the Advanced Gamma Tracking Array: AGATA. Korten, W.; Atac, A.; Beaumel, D.; Bednarczyk, P.; Bentley, M. A.; Benzoni, G.; Boston, A.; Bracco, A.; Cederkäll, J.; Cederwall, B.; Ciemała, M.; Clément, E.; Crespi, F. C. L.; Curien, D.; de Angelis, G.; Didierjean, F.; Doherty, D. T.; Dombradi, Zs; Duchêne, G.; Dudek, J.; Fernandez-Dominguez, B.; Fornal, B.; Gadea, A.; Gaffney, L. P.; Gerl, J.; Gladnishki, K.; Goasduff, A.; Górska, M.; Greenlees, P. T.; Hess, H.; Jenkins, D. G.; John, P. R.; Jungclaus, A.; Kmiecik, M.; Korichi, A.; Labiche, M.; Leoni, S.; Ljungvall, J.; Lopez-Martens, A.; Maj, A.; Mengoni, D.; Million, B.; Nannini, A.; Napoli, D.; Nolan, P. J.; Nyberg, J.; Obertelli, A.; Pakarinen, J.; Pietralla, N.; Podolyák, Zs; Quintana, B.; Raabe, R.; Rainovski, G.; Recchia, F.; Reiter, P.; Rudolph, D.; Simpson, J.; Theisen, Ch; Tonev, D.; Tumino, A.; Valiente-Dobón, J. J.; Wieland, O.; Wimmer, K.; Zielińska, M.; Collaboration, the AGATA in The European Physical Journal A (2020). 56(5) 137--.
New physics opportunities are opening up by the Advanced Gamma Tracking Array, AGATA, as it evolves to the full 4\($$\)pi \($$\)π instrument. AGATA is a high-resolution \($$\)gamma \($$\)γ-ray spectrometer, solely built from highly segmented high-purity Ge detectors, capable of measuring \($$\)gamma \($$\)γ rays from a few tens of keV to beyond 10 MeV, with unprecedented efficiency, excellent position resolution for individual \($$\)gamma \($$\)γ-ray interactions, and very high count-rate capability. As a travelling detector AGATA will be employed at all major current and near-future European research facilities delivering stable and radioactive ion beams.
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Compex: a cubic germanium detector. Såmark-Roth, A.; Cox, D. M.; Eberth, J.; Golubev, P.; Rudolph, D.; Sarmiento, L. G.; Tocabens, G.; Ginsz, M.; Pirard, B.; Quirin, P. in The European Physical Journal A (2020). 56(5) 141.
The Compex detector is an electrically cooled, composite germanium detector that uses four coaxial, cubic-shaped, single-encapsulated germanium crystals. This novel detector allows for new heights in photon detection efficiency in decay spectroscopy setups using box-shaped vacuum chambers. Its spectroscopic performance and detection efficiency is evaluated by means of source measurements. Motivated by Compex's unique cubic germanium crystals, the Lund scanning system has been developed. The constructed system is used to characterise the response as a function of interaction position within a Compex crystal. Sensitivity across the front face, pulse shapes, and rise times have been analysed. Future development and applications of the Compex detector are discussed.
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Benchmarking the PreSPEC@GSI experiment for Coulex-multipolarimetry on the π(p3/2) --> π(p1/2) spin-flip transition in 85Br. Napiralla, P.; Lettmann, M.; Stahl, C.; Rainovski, G.; Pietralla, N.; Afara, S.; Ameil, F.; Arici, T.; Aydin, S.; Barrientos, D.; Bednarczyk, P.; Bentley, M. A.; Benzoni, G.; Birkenbach, B.; Blazhev, A.; Boston, A. J.; Boutachkov, P.; Bracco, A.; Bruyneel, B.; Cl{é}ment, E.; Cort{é}s, M. L.; Crespi, F. C. L.; Cullen, D. M.; Curien, D.; D{é}sesquelles, P.; Didierjean, F.; Domingo-Pardo, C.; Duch{ê}ne, G.; Eberth, J.; Egger, H.; Fahlander, C.; Gerl, J.; Gladnishki, K. A.; Golubev, P.; Gonz{á}lez, V.; G{ó}rska, M.; Gottardo, A.; Grassi, L.; Habermann, T.; Harkness-Brennan, L. J.; Hess, H.; Jenkins, D. G.; John, P. R.; Jolie, J.; Judson, D. S.; Kojouharov, I.; Korten, W.; Labiche, M.; Lalovi{{{'c}}}, N.; Lizarazo, C.; Louchart-Henning, C.; Maj, A.; Menegazzo, R.; Mengoni, D.; Merchan, E.; Million, B.; M{ö}ller, O.; M{ö}ller, T.; Moschner, K.; Modamio, V.; Napoli, D.; Singh, B. S. Nara; Podoly{á}k, Zs.; Pietri, S.; Ralet, D.; Reese, M.; Reiter, P.; Rudolph, D.; Sanchis, E.; Sarmiento, L. G.; Schaffner, H.; Simpson, J.; Singh, P. P.; Valiente-Dob{ó}n, J. J.; Werner, V.; Wieland, O. in The European Physical Journal A (2020). 56(5) 147.
A first performance test of the Coulomb excitation multipolarimetry (Coulex-multipolarimetry) method is presented. It is based on a {\\($}{\$\)}^{\{}85{\}}{backslash}hbox {\{}Br{\}}{\backslash},{backslash}pi p{\_}{\{}3/2{\}}{backslash}rightarrow {backslash}pi p{\_}{\{}1/2{\}}{\\($}{\$\)}85Br\($\pi$\)p3/2{\textrightarrow}\($\pi$\)p1/2 spin-flip experiment performed as part of the PreSPEC-AGATA campaign at the GSI Helmholtzzentrum f{ü}r Schwerionenforschung (GSI). Via determination of background levels around the expected {\\($}{\$\)}^{\{}85{\}}{backslash}hbox {\{}Br{\}}{\\($}{\$\)}85Br excitations as well as measured {\\($}{\$\)}^{\{}197{\}}{backslash}hbox {\{}Au{\}}{\\($}{\$\)}197Au excitations, an upper limit for the M1 transition strength of the {\\($}{\$\)}1/2{\_}1^-{backslash}rightarrow 3/2{\_}{backslash}text {\{}g.s.{\}}^-{\\($}{\$\)}1/21-{textrightarrow}3/2g.s.- transition in {\\($}{\$\)}^{\{}85{\}}{backslash}hbox {\{}Br{\}}{\\($}{\$\)}85Br and a lower beam time limit for upcoming experimental campaigns utilizing Coulex-multipolarimetry have been inferred. The impact of the use of AGATA in its anticipated {\\($}{\$\)}1{backslash}pi {\\($}{\$\)}1\($\pi$\) configuration on these estimates is deduced via Geant4 simulations.
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Octupole states in 207Tl studied through β decay. Berry, T. A.; Podolyák, Zs.; Carroll, R. J.; Lică, R.; Brown, B. A.; Grawe, H.; Sotty, Ch.; Timofeyuk, N. K.; Alexander, T.; Andreyev, A. N.; Ansari, S.; Borge, M. J. G.; Brunet, M.; Cresswell, J. R.; Fahlander, C.; Fraile, L. M.; Fynbo, H. O. U.; Gamba, E.; Gelletly, W.; Gerst, R.-B.; Górska, M.; Gredley, A.; Greenlees, P.; Harkness-Brennan, L. J.; Huyse, M.; Judge, S. M.; Judson, D. S.; Konki, J.; Kowalska, M.; Kurcewicz, J.; Kuti, I.; Lalkovski, S.; Lazarus, I.; Lund, M.; Madurga, M.; Mărginean, N.; Mărginean, R.; Marroquin, I.; Mihai, C.; Mihai, R. E.; Nácher, E.; Negret, A.; Nae, S.; Niţă, C.; Pascu, S.; Page, R. D.; Patel, Z.; Perea, A.; Phrompao, J.; Piersa, M.; Pucknell, V.; Rahkila, P.; Rapisarda, E.; Regan, P. H.; Rotaru, F.; Rudigier, M.; Shand, C. M.; Shearman, R.; Simpson, E. C.; Stegemann, S.; Stora, T.; Tengblad, O.; Turturica, A.; Van Duppen, P.; Vedia, V.; Walker, P. M.; Warr, N.; Wearing, F. P.; H., De Witte in Phys. Rev. C, (A. P. Society, Hrsg.) (2020). 101 054311.
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Shape coexistence and multiparticle-multihole structures in 110,112Cd. Garrett, P. E.; Rodríguez, T. R.; Diaz Varela, A.; Green, K. L.; Bangay, J.; Finlay, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D. S.; Bildstein, V.; Colosimo, S.; Cross, D. S.; Demand, G. A.; Finlay, P.; Garnsworthy, A. B.; Grinyer, G. F.; Hackman, G.; Jigmeddorj, B.; Jolie, J.; Kulp, W. D.; Leach, K. G.; Morton, A. C.; Orce, J. N.; Pearson, C. J.; Phillips, A. A.; Radich, A. J.; Rand, E. T.; Schumaker, M. A.; Svensson, C. E.; Sumithrarachchi, C.; Triambak, S.; Warr, N.; Wong, J.; Wood, J. L.; Yates, S. W. in Phys. Rev. C (2020). 101 044302.
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γ-ray Spectroscopy of 85Se Produced in 232Th Fission. Adamska, E.; Korgul, A.; Fijałkowska, A.; Miernik, K.; Piersa, A.; Canavan, R.; Etasse, D.; Jovančević, N.; Lebois, M.; Rudigier, M.; Thisse, D.; Wilson, J.N.; Adsley, P.; Algora, A.; Babo, M.; Belvedere, K.; Benito, J.; Blazhev, A.; Benzoni, G.; Boso, A.; Bottoni, S.; Bunce, M.; Chakma, R.; Cieplicka-Oryńczak, N.; Ciemała, M.; Collins, S.; Cortés, L.; Davies, P.; Delafosse, C.; Fallot, M.; Fornal, B.; Fraile, L.M.; Gerst, R.-B.; Gjestvang, D.; Gottardo, A.; Guadilla, V.; Hafner, G.; Hauschild, K.; Heine, M.; Henrich, C.; Homm, I.; Ibrahim, F.; Iskra, Ł.W.; Koseoglou, P.; Kröll, T.; Kurtukian-Nieto, T.; Le meur, L.; Leoni, S.; Ljungvall, J.; Lopez-Martens, A.; Lozeva, R.; Matea, I.; Nemer, J.; Oberstedt, S.; Paulsen, W.; Popovitch, Y.; Qi, L.; Ralet, D.; Regan, P.H.; Reygadas Tello, D.; Rezynkina, K.; Sánchez-Tembleque, V.; Schmitt, C.; Söderström, P.-A.; Surder, C.; Tocabens, G.; Vedia, V.; Verney, D.; Warr, N.; Wasilewska, B.; Wiederhold, J.; Yavahchova, M.; Zeiser, F. in Acta. Phys. Pol. (2020). B 51 843-848.
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γ-ray tracking with AGATA: A new perspective for spectroscopy at radioactive ion beam facilities. Reiter, P. in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms (2020). 463 221 - 226.
The Advanced GAmma Tracking Array (AGATA) is a next generation high-resolution γ-ray spectrometer for nuclear structure studies based on the principle of γ-ray tracking. It is built from high-fold segmented germanium detectors which will operate in position-sensitive mode by employing digital electronics and pulse-shape decomposition algorithms. The unique combination of highest detection efficiency and position sensitivity allows spectroscopic studies with instable ion beams of lowest intensity. The first implementation of the array consisted of five AGATA modules; it was operated at INFN Legnaro. A larger array of AGATA modules was used at GSI for experiments with unstable ion beams at relativistic energies. At the moment the spectrometer is hosted by GANIL. In the near future AGATA will be employed at the leading infrastructures for nuclear structure studies in Europe. The presentation will illustrate the potential of the novel gamma-ray tracking method by physics cases from the different exploitation sites. Perspectives and opportunities for γ-ray spectroscopy at future radioactive ion beam facilities are presented and discussed.
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Search for proton emission of the isomeric 10+ state in Ni-54. Stahl, K.; Wendt, A.; Reiter, P.; Rudolph, D.; Blazhev, A.; Bruyneel, B.; Eberth, J.; Fahlander, C.; Fransen, C.; Golubev, P.; Hess, H.; Hoischen, R.; Holler, A.; Kalkühler, M.; Kotthaus, T.; Lersch, D.; Pascovici, G.; Seidlitz, M.; Siebeck, B.; Taprogge, J.; Warr, N.; Wiens, A.; Zell, O. in The European Physical Journal A (2020). 56(1) 22.
Several experiments were conducted at the 10 MV Van-de-Graaff tandem accelerator at the Institute of Nuclear Physics, Cologne, to detect proton emission from the isomeric 6457-keV {\\($}{\$\)}10^+{\\($}{\$\)}10+ state in {\\($}{\$\)}^{\{}54{\}}{backslash}hbox {\{}Ni{\}}{\\($}{\$\)}54Ni. Excitation functions for two fusion--evaporation reactions were measured to maximise the population of the rare two-neutron evaporation channel from a {\\($}{\$\)}^{\{}56{\}}{backslash}hbox {\{}Ni{\}}{\\($}{\$\)}56Ni compound nucleus. The search for delayed proton emission was based on the {\\($}{\$\)}^{\{}28{\}}{backslash}hbox {\{}Si{\}}{\\($}{\$\)}28Si({\\($}{\$\)}^{\{}28{\}}{backslash}hbox {\{}Si{\}},2n{\\($}{\$\)}28Si,2n){\\($}{\$\)}^{\{}54{\}}{backslash}hbox {\{}Ni{\}}{\\($}{\$\)}54Ni reaction at a beam energy of 70 MeV. For this reaction, a cross-section limit for the population of the {\\($}{\$\)}10^+{\\($}{\$\)}10+ state in {\\($}{\$\)}^{\{}54{\}}{backslash}hbox {\{}Ni{\}}{\\($}{\$\)}54Ni and its proton-decay branch was determined to be {\\($}{\$\)}{backslash}sigma < 22{\\($}{\$\)}\($\sigma$\)<22 nb.
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Pairing-quadrupole interplay in the neutron-deficient tin nuclei: First lifetime measurements of low-lying states in 106,108Sn. Siciliano, M.; Valiente-Dobón, J.J; Goasduff, A.; Nowacki, F.; Zuker, A.P; Bazzacco, D.; Lopez-Martens, A.; Clément, E.; Benzoni, G.; Braunroth, T.; Crespi, F.C.L; Cieplicka-Oryńczak, N.; Doncel, M.; Ertürk, S.; de France, G.; Fransen, C.; Gadea, A.; Georgiev, G.; Goldkuhle, A.; Jakobsson, U.; Jaworski, G.; John, P.R; Kuti, I.; Lemasson, A.; Marchi, T.; Mengoni, D.; Michelagnoli, C.; Mijatović, T.; Müller-Gatermann, C.; Napoli, D.R; Nyberg, J.; Palacz, M.; Pérez-Vidal, R.M; Sayği, B.; Sohler, D.; Szilner, S.; Testov, D.; Zielińska, M.; Barrientos, D.; Birkenbach, B.; Boston, H.C; Boston, A.J; Cederwall, B.; Collado, J.; Cullen, D.M; Désesquelles, P.; Domingo-Pardo, C.; Dudouet, J.; Eberth, J.; Egea-Canet, F.J; González, V.; Harkness-Brennan, L.J; Hess, H.; Judson, D.S; Jungclaus, A.; Korten, W.; Labiche, M.; Lefevre, A.; Leoni, S.; Li, H.; Maj, A.; Menegazzo, R.; Million, B.; Pullia, A.; Recchia, F.; Reiter, P.; Salsac, M.D; Sanchis, E.; Stezowski, O.; Theisen, Ch in Physics Letters B (2020). 806 135474--.
The lifetimes of the low-lying excited states 2+ and 4+ have been directly measured in the neutron-deficient 106,108Sn isotopes. The nuclei were populated via a deep-inelastic reaction and the lifetime measurement was performed employing a differential plunger device. The emitted γ rays were detected by the AGATA array, while the reaction products were uniquely identified by the VAMOS++ magnetic spectrometer. Large-Scale Shell-Model calculations with realistic forces indicate that, independently of the pairing content of the interaction, the quadrupole force is dominant in the B(E2;21+→0g.s.+) values and it describes well the experimental pattern for 104−114Sn; the B(E2;41+→21+) values, measured here for the first time, depend critically on a delicate pairing-quadrupole balance, disclosed by the very precise results in 108Sn.
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Performing the differential decay curve method on γ-ray transitions with unresolved Doppler-shifted components. Barber, L.; Cullen, D.M.; Giles, M.M.; Singh, B.S. Nara; Mallaburn, M.J.; Beckers, M.; Blazhev, A.; Braunroth, T.; Dewald, A.; Fransen, C.; Goldkuhle, A.; Jolie, J.; Mammes, F.; Müller-Gatermann, C.; Wölk, D.; Zell, K.O. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2020). 950 162965.
A new method of extracting the γ-ray intensities necessary to perform lifetime measurements using the differential decay curve method (DDCM) is presented in this work, the unresolved Doppler-shifted components method (UDCM). The UDCM allows for a DDCM analysis to be performed using a γ-ray transition for which the fully Doppler-shifted and degraded components are unresolvable in energy and so are detected as a single peak. This technique was used to measure the known lifetime of the yrast 21+ state in 50Mn with a depopulating transition that does not have resolvable fully Doppler-shifted and degraded components. The lifetime measured through applying the UDCM was consistent with the standard DDCM measurement of the 21+ state. Use of the UDCM allows for DDCM lifetime measurements to be made using transitions of smaller γ-ray energies, smaller recoil velocities and, in some cases, with a smaller uncertainty. In contrast to a standard DDCM analysis, a UDCM analysis is also independent of the widths of the fully Doppler-shifted and degraded components and as a result they do not need to be determined.
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Detailed spectroscopy of doubly magic 132 Sn. Benito, J.; Fraile, L. M.; Korgul, A.; Piersa, M.; Adamska, E.; Andreyev, A. N.; Álvarez-Rodríguez, R.; Barzakh, A. E.; Benzoni, 6 G.; Berry, T.; Borge, M. J. G.; Carmona, M.; Chrysalidis, K.; Costache, C.; Cubiss, J. G.; Goodacre, T. Day; Witte, H. De; Fedorov, D. V.; Fedosseev, V. N.; Fernández-Martínez, G.; Fijałkowska, A.; Fila, M.; Fynbo, H.; Galaviz, D.; Galve, P.; García-Díez, M.; Greenlees, P. T.; Grzywacz, R.; Harkness-Brennan, L. J.; Henrich, C.; Huyse, M.; Ibáñez, P.; Illana, A.; Janas, Z.; Jolie, J.; Judson, D. S.; Karayonchev, V.; Kicińska-Habior, M.; Konki, J.; Kurcewicz, J.; Lazarus, I.; Lică, R.; López-Montes, A.; Lund, M.; Mach, H.; Madurga, M.; Marroquín, I.; Marsh, B.; Martínez, M. C.; Mazzocchi, C.; Mărginean, N.; Mărginean, R.; Miernik, K.; Mihai, C.; Mihai, R. E.; Nácher, E.; Negret, A.; Olaizola, B.; Page, R. D.; Paulauskas, S. V.; Pascu, S.; Perea, A.; Pucknell, V.; Rahkila, P.; Raison, C.; Rapisarda, E.; Régis, J.-M.; Rezynkina, K.; Rotaru, F.; Rothe, S.; Sánchez-Parcerisa, D.; Sánchez-Tembleque, V.; Schomacker, K.; Simpson, G. S.; Sotty, Ch.; Stan, L.; Stănoiu, M.; Stryjczyk, M.; Tengblad, O.; Turturica, A.; Udías, J. M.; Duppen, P. Van; Vedia, V.; Villa-Abaunza, A.; Viñals, S.; Walters, W. B.; Wadsworth, R.; Warr, N. in Phys. Rev. C (2020). (102) 014328.
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Multi-quasiparticle sub-nanosecond isomers in W-178. Rudigier, M.; Walker, P.M.; Canavan, R.L.; Podolyák, Zs.; Regan, P.H.; Söderström, P.-A.; Lebois, M.; Wilson, J.N.; Jovancevic, N.; Blazhev, A.; Benito, J.; Bottoni, S.; Brunet, M.; Cieplicka-Orynczak, N.; Courtin, S.; Doherty, D.T.; Fraile, L.M.; Hadynska-Klek, K.; Heine, M.; Iskra, Ł.W.; Jolie, J.; Karayonchev, V.; Kennington, A.; Koseoglou, P.; Lotay, G.; Lorusso, G.; Nakhostin, M.; Nita, C.R.; Oberstedt, S.; Qi, L.; Régis, J.-M.; Sánchez-Tembleque, V.; Shearman, R.; Witt, W.; Vedia, V.; Zell, K.O. in Physics Letters B (2020). 801 135140.
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Isomer studies in the vicinity of the doubly-magic nucleus 100Sn: Observation of a new low-lying isomeric state in 97Ag. Hornung, Christine; Amanbayev, Daler; Dedes, Irene; Kripko-Koncz, Gabriella; Miskun, Ivan; Shimizu, Noritaka; Andrés, Samuel Ayet San; Bergmann, Julian; Dickel, Timo; Dudek, Jerzy; Ebert, Jens; Geissel, Hans; Górska, Magdalena; Grawe, Hubert; Greiner, Florian; Haettner, Emma; Otsuka, Takaharu; Plaß, Wolfgang R.; Purushothaman, Sivaji; Rink, Ann-Kathrin; Scheidenberger, Christoph; Weick, Helmut; Bagchi, Soumya; Blazhev, Andrey; Charviakova, Olga; Curien, Dominique; Finlay, Andrew; Kaur, Satbir; Lippert, Wayne; Otto, Jan-Hendrik; Patyk, Zygmunt; Pietri, Stephane; Tanaka, Yoshiki K.; Tsunoda, Yusuke; Winfield, John S. in Physics Letters B (2020). 802 135200.
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γ-γ fast timing at X-ray energies and investigation on various timing deviations. Régis, J.-M.; Esmaylzadeh, A.; Jolie, J.; Karayonchev, V.; Knafla, L.; Köster, U.; Kim, Y.H.; Strub, E. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2020). 955 163258.
We report on systematic γ-γ fast-timing measurements by using four cylindrical 1.5′′×1.5′′ LaBr3(Ce) scintillator detectors which were installed in compact geometry around the focal plane of the Lohengrin fission-fragment separator at the Institut Laue–Langevin in Grenoble, France. Unconventional γ-ray sources as 185Os and 187W were produced by thermal-neutron activation to provide nearly prompt low-energy γ and K-X rays with average γ- and X-ray multiplicity equal to two. Due to practically no contribution of Compton background, highly precise results of time-walk measurements down to 40 keV are presented. Timing deviations related to different phenomena have been investigated, such as the geometry of an extended γ-ray source and the detector arrangement, long-term timing shifts and the timing contributions of the Compton background and the inter-detector Compton-scattering. The geometrical timing deviations are shown to be minimized using a multi-element detector array with a centrally symmetric arrangement relative to the center of the focal plane. Time-correction formula are proposed as analytical corrections for long-term time shifts, the time contributions of the Compton background and the position-dependent change of the time walk for cases where the calibration source cannot be placed at the center of the focal plane.
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Low-Z boundary of the N=88-90 shape phase transition: Ce-148 near the critical point. Koseoglou, P.; Werner, V.; Pietralla, N.; Ilieva, S.; Nikšić, T.; Vretenar, D.; Alexa, P.; Thürauf, M.; Bernards, C.; Blanc, A.; Bruce, A. M.; Cakirli, R. B.; Cooper, N.; Fraile, L. M.; de France, G.; Jentschel, M.; Jolie, J.; Köster, U.; Korten, W.; Kröll, T.; Lalkovski, S.; Mach, H.; Mărginean, N.; Mutti, P.; Patel, Z.; Paziy, V.; Podolyák, Zs.; Regan, P. H.; Régis, J.-M.; Roberts, O. J.; Saed-Samii, N.; Simpson, G. S.; Soldner, T.; Ur, C. A.; Urban, W.; Wilmsen, D.; Wilson, E. in Phys. Rev. C (2020). 101(1) 014303.
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Evolution of Octupole Deformation in Radium Nuclei from Coulomb Excitation of Radioactive Ra-222 and Ra-228 Beams. Butler, P. A.; Gaffney, L. P.; Spagnoletti, P.; Abrahams, K.; Bowry, M.; Cederkäll, J.; de Angelis, G.; De Witte, H.; Garrett, P. E.; Goldkuhle, A.; Henrich, C.; Illana, A.; Johnston, K.; Joss, D. T.; Keatings, J. M.; Kelly, N. A.; Komorowska, M.; Konki, J.; Kröll, T.; Lozano, M.; Nara Singh, B. S.; O'Donnell, D.; Ojala, J.; Page, R. D.; Pedersen, L. G.; Raison, C.; Reiter, P.; Rodriguez, J. A.; Rosiak, D.; Rothe, S.; Scheck, M.; Seidlitz, M.; Shneidman, T. M.; Siebeck, B.; Sinclair, J.; Smith, J. F.; Stryjczyk, M.; Van Duppen, P.; Vinals, S.; Virtanen, V.; Warr, N.; Wrzosek-Lipska, K.; Zielińska, M. in Phys. Rev. Lett. (2020). 124(4) 042503.
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Spectroscopy of 99Cd and 101In from beta decays of 99In and 101Sn. Park, J.; Krücken, R.; Blazhev, A.; Lubos, D.; Gernhäuser, R.; Lewitowicz, M.; Nishimura, S.; Ahn, D. S.; Baba, H.; Blank, B.; Boutachkov, P.; Browne, F.; ifmmode \check{C}else \v{C}\fi{}elikoviifmmode \acute{c}else {{\'c}}\fi{}, I.; de France, G.; Doornenbal, P.; Faestermann, T.; Fang, Y.; Fukuda, N.; Giovinazzo, J.; Goel, N.; Górska, M.; Grawe, H.; Ilieva, S.; Inabe, N.; Isobe, T.; Jungclaus, A.; Kameda, D.; Kim, G. D.; Kim, Y.-K.; Kojouharov, I.; Kubo, T.; Kurz, N.; Kwon, Y. K.; Lorusso, G.; Moschner, K.; Murai, D.; Nishizuka, I.; Patel, Z.; Rajabali, M. M.; Rice, S.; Sakurai, H.; Schaffner, H.; Shimizu, Y.; Sinclair, L.; Söderström, P.-A.; Steiger, K.; Sumikama, T.; Suzuki, H.; Takeda, H.; Wang, Z.; Watanabe, H.; Wu, J.; Xu, Z. Y. in Phys. Rev. C (2020). 102(1) 014304.
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Lifetime measurements in the odd-A nucleus 177Hf. Knafla, L.; Alexa, P.; Köster, U.; Thiamova, G.; Régis, J.-M.; Jolie, J.; Blanc, A.; Bruce, A. M.; Esmaylzadeh, A.; Fraile, L. M.; de France, G.; Häfner, G.; Ilieva, S.; Jentschel, M.; Karayonchev, V.; Korten, W.; Kröll, T.; Lalkovski, S.; Leoni, S.; Mach, H.; Marginean, N.; Mutti, P.; Pascovici, G.; Paziy, V.; Podolyák, Zs.; Regan, P. H.; Roberts, O. J.; Saed-Samii, N.; Simpson, G. S.; Smith, J. F.; Soldner, T.; Townsley, C.; Ur, C. A.; Urban, W.; Vancraeyenest, A.; Warr, N. in Phys. Rev. C (2020). 102(5) 054322.
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Operating the 120{textdegree} Dipol-Magnet at the {CologneAMS} in a gas-filled mode. Altenkirch, R.; Feuerstein, C.; Schiffer, M.; Hackenberg, G.; Heinze, S.; Müller-Gatermann, C.; Dewald, A. in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms (2019). 438 184--188.
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Lifetime measurements in 52,54Ti to study shell evolution toward N=32. Goldkuhle, A.; Fransen, C.; Blazhev, A.; Beckers, M.; Birkenbach, B.; Braunroth, T.; Clément, E.; Dewald, A.; Dudouet, J.; Eberth, J.; Hess, H.; Jacquot, B.; Jolie, J.; Kim, Y.-H.; Lemasson, A.; Lenzi, S. M.; Li, H. J.; Litzinger, J.; Michelagnoli, C.; Müller-Gatermann, C.; Nara Singh, B. S.; Pérez-Vidal, R. M.; Ralet, D.; Reiter, P.; Vogt, A.; Warr, N.; Zell, K. O.; Ataç, A.; Barrientos, D.; Barthe-Dejean, C.; Benzoni, G.; Boston, A. J.; Boston, H. C.; Bourgault, P.; Burrows, I.; Cacitti, J.; Cederwall, B.; Ciemala, M.; Cullen, D. M.; De France, G.; Domingo-Pardo, C.; Foucher, J.-L.; Fremont, G.; Gadea, A.; Gangnant, P.; González, V.; Goupil, J.; Henrich, C.; Houarner, C.; Jean, M.; Judson, D. S.; Korichi, A.; Korten, W.; Labiche, M.; Lefevre, A.; Legeard, L.; Legruel, F.; Leoni, S.; Ljungvall, J.; Maj, A.; Maugeais, C.; Ménager, L.; Ménard, N.; Menegazzo, R.; Mengoni, D.; Million, B.; Munoz, H.; Napoli, D. R.; Navin, A.; Nyberg, J.; Ozille, M.; Podolyak, Zs.; Pullia, A.; Raine, B.; Recchia, F.; Ropert, J.; Saillant, F.; Salsac, M. D.; Sanchis, E.; Schmitt, C.; Simpson, J.; Spitaels, C.; Stezowski, O.; Theisen, Ch.; Toulemonde, M.; Tripon, M.; Valiente Dobón, J.-J.; Voltolini, G.; Zielińska, M. in Phys. Rev. C (2019). 100(5) 054317.
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STUDY OF DIPOLE EXCITATIONS IN Sn-124 VIA (p, p `gamma) AT 15 MeV. Faerber, M.; Bohn, A.; Everwyn, V; Muescher, M.; Pickstone, S. G.; Prill, S.; Scholz, P.; Spieker, M.; Weinert, M.; Wilhelmy, J.; Zilges, A. in Acta Physica Polonica B (2019). 50(3) 475-480.
An inelastic proton scattering experiment was performed with the combined setup SONIC@HORUS at a beam energy of 15 MeV in Cologne. First results for the deduced branching ratios as well as the E1 strength distribution obtained with the Sn-124(p, p'gamma) reaction are presented. Additionally, a qualitative comparison to excitations in experiments with different probes like (alpha, alpha'gamma) and (gamma, gamma') will be discussed.
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Lifetimes of the \(${4}_{1}^{+}$\) states of 206Po and 204Po: A study of the transition from noncollective seniority-like mode to collectivity. Stoyanova, M.; Rainovski, G.; Jolie, J.; Pietralla, N.; Blazhev, A.; Beckers, M.; Dewald, A.; Djongolov, M.; Esmaylzadeh, A.; Fransen, C.; Gerhard, L. M.; Gladnishki, K. A.; Herb, S.; John, P. R.; Karayonchev, V.; Keatings, J. M.; Kern, R.; Knafla, L.; Kocheva, D.; Kornwebel, L.; Kröll, Th.; Ley, M.; Mashtakov, K. M.; Müller-Gatermann, C.; Régis, J.-M.; Scheck, M.; Schomacker, K.; Sinclair, J.; Spagnoletti, P.; Sürder, C.; Warr, N.; Werner, V.; Wiederhold, J. in Phys. Rev. C (2019). 100(6) 064304.
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Low-lying dipole strength in the well-deformed nucleus Gd-156. Tamkas, M.; Aciksoez, E.; Isaak, J.; Beck, T.; Benouaret, N.; Bhike, M.; Boztosun, I.; Durusoy, A.; Gayer, U.; Krishichayan,; Loeher, B.; Pietralla, N.; Savran, D.; Tornow, W.; Werner, V.; Zilges, A.; Zweidinger, M. in Nuclear Physics A (2019). 987 79-89.
The low-lying dipole strength of the deformed nucleus Gd-156 was investigated in the energy region from 3.1 MeV to 6.2 MeV using the method of nuclear resonance fluorescence (NRF). The NRF experiments were performed at the Darmstadt High Intensity Photon Setup (DHIPS) at Technische Universitat Darmstadt using unpolarized continuous-energy bremsstrahlung and at the High-Intensity gamma-ray Source (HI gamma S) at Duke University using quasi-monoenergetic and linearly-polarized photon beams. The combination of both experiments allows to separate electric and magnetic contributions and to determine absolute transition strengths for individual excited states as well as averaged quantities over narrow excitation energy regions. The investigated energy regions cover the region of the scissors mode as well as the low-energy part of the Pygmy Dipole Resonance. This is the first experiment where both of these excitation modes as well as the region in between has been successfully studied in a deformed heavy nucleus using the NRF method. (C) 2019 Elsevier B.V. All rights reserved.
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The concept of nuclear photon strength functions: A model-independent approach via ((gamma)over-right-arrow, gamma ` gamma `') reactions. Isaak, J.; Savran, D.; Loher, B.; Beck, T.; Bhike, M.; Gayer, U.; Krishichayan,; Pietralla, N.; Scheck, M.; Tornow, W.; Werner, V.; Zilges, A.; Zweidinger, M. in Physics Letters B (2019). 788 225-230.
Most theoretical approaches used in nuclear astrophysics to model the nucleosynthesis of heavy elements incorporate the so-called statistical model in order to describe the excitation and decay properties of atomic nuclei. One of the basic assumptions of this model is the validity of the Brink-Axel hypothesis and the related concept of so-called photon strength functions to describe gamma-ray transition probabilities. We present a novel experimental approach that allows for the first time to experimentally determine the photon strength function simultaneously in two independent ways by a unique combination of quasimonochromatic photon beams and a newly implemented gamma-gamma coincidence setup. This technique does not assume a priori the validity of the Brink-Axel hypothesis and sets a benchmark in terms of the detection sensitivity for measuring decay properties of photo-excited states below the neutron separation energy. The data for the spherical off-shell nucleus Te-128 were obtained for y-ray beam-energy settings between 3 MeV and 9 MeV in steps of 130 keV for the lower beam energies and in steps of up to 280 keV for the highest beam settings. We present a quantitative analysis on the consistency of the derived photon strength function with the Brink-Axel hypothesis. The data clearly demonstrate a discrepancy of up to a factor of two between the photon strength functions extracted from the photoabsorption and photon emission process, respectively. In addition, we observe that the photon strength functions are not independent of the excitation energy, as usually assumed. Thus, we conclude, that the Brink-Axel hypothesis is not strictly fulfilled in the excitation-energy region below the neutron separation threshold S-n= 8.78 MeV) for the studied case of Te-128. (C) 2018 The Authors. Published by Elsevier B.V.
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HIGH-RESOLUTION GAMMA-RAY SPECTROSCOPY WITH ELIADE AT THE EXTREME LIGHT INFRASTRUCTURE. Soderstrom, P-A; Suliman, G.; Ur, C. A.; Balabanski, D.; Beck, T.; Capponi, L.; Dhal, A.; Iancu, V; Ilie, S.; Iovea, M.; Kusoglu, A.; Petcu, C.; Pietralla, N.; {Turturica, V}; Udup, E.; Wilhelmy, J.; Zilges, A. in Acta Physica Polonica B (2019). 50(3) 329-338.
The Extreme Light Infrastructure is a major European undertaking with the aim of constructing a set of facilities that can produce the worlds highest intensity laser beams as well as unique high-brilliance, narrow-bandwidth gamma-ray beams using laser-based inverse Compton scattering. The latter will be one of the unique features of the facility in Bucharest-Magurele, Romania, where the scientific focus will be towards Nuclear Physics And nuclear photonics both with high intensity lasers and gamma beams individually, as well as combined. One of the main instruments being constructed for the Nuclear Physics And applications with high-brilliance gamma-beams research activity is the ELIADE gamma-ray detector array. This array consists of eight segmented HPGe clover detectors as well as large-volume LaBr3 detectors. The nuclear physics topics are expected to cover a large range including, but not limited to, properties of pygmy resonance and collective scissors mode excitations, parity violation in nuclear excitations, and matrix elements for neutrinoless double-beta decay. However, the uniqueness of the environment in which ELIADE will operate presents several challenges in the design and construction of the array. Here, we discuss some of these challenges and how we plan to overcome them, as well as the current status of implementation.
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Cross section measurements of proton capture reactions on Mo isotopes relevant to the astrophysical p process. Foteinou, V.; Axiotis, M.; Harissopulos, S.; Dimitriou, P.; Provatas, G.; Lagoyannis, A.; Becker, H. W.; Rogalla, D.; Zilges, A.; Schreckling, A.; Endres, A. in The European Physical Journal A (2019). 55(5)
.Cross section measurements of (p,) reactions on the Mo isotopes have been performed at beam energies from 2 to 6.2 MeV that are relevant to the p-process. Partial cross sections and isomeric ratios were also determined for the Mo-92 case. Astrophysical S factors as well as reaction rates were derived from the experimental cross sections. Statistical model calculations were performed using the latest version (1.9) of the statistical model code TALYS and were compared with the new data. An overall good agreement between theory and experiment was found. In addition, the effect of different combinations of the nuclear input parameters entering the stellar reaction-rate calculations was investigated. It was found that, for certain combinations of optical-model potentials, nuclear level densities and -ray strength functions, the nuclear uncertainties propagated through the Hauser-Feshbach calculations are less than a factor of 2 which is well below the average discrepancies of the calculated p-nuclei abundances and the observations.
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Atome, Kerne, Quarks – Alles begann mit Rutherford: Wie Teilchen-Streuexperimente uns die subatomare Welt erklären Paetz gen. Schieck, Hans (2019). Springer Spektrum.
Hans Paetz gen. Schieck zeigt in diesem essential nicht nur, wie rasant sich das Gebiet der Atome, Kerne und Teilchen bis zu den Quarks und Gluonen entwickelt hat. Er erläutert auch, wie alles begonnen hat – hier spielt die Person von Ernest Rutherford eine alles überragende Rolle. Das Gebiet der Kernphysik und unser Wissen über die Kerne haben sich seit 100 Jahren fundamental gewandelt. Aus eher philosophischen Vorstellungen haben sich konkrete Kenntnisse entwickelt über die Bausteine unserer Welt, deren Größe und hierarchische Ordnung und darüber, welche fundamentalen Kräfte zwischen ihnen wirken.
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Beta decay of 133In: gamma emission from neutron-unbound states in 133Sn. Piersa, M.; Korgul, A.; Fraile, L. M.; Benito, J.; Adamska, E.; Andreyev, A. N.; Álvarez-Rodr\'{i}guez, R.; Barzakh, A. E.; Benzoni, G.; Berry, T.; Borge, M. J. G.; Carmona, M.; Chrysalidis, K.; Correia, J. G.; Costache, C.; Cubiss, J. G.; Day Goodacre, T.; De Witte, H.; Fedorov, D. V.; Fedosseev, V. N.; Fernández-Mart\'{i}nez, G.; Fija\l{}kowska, A.; Fila, M.; Fynbo, H.; Galaviz, D.; Greenlees, P. T.; Grzywacz, R.; Harkness-Brennan, L. J.; Henrich, C.; Huyse, M.; Illana, A.; Janas, Z.; Johnston, K.; Judson, D. S.; Karanyonchev, V.; Kiciifmmode \acute{n}else {{\'n}}\fi{}ska Habior, M.; Konki, J.; Kurcewicz, J.; Lazarus, I.; Licifmmode \u{a}else \u{a}\fi{}, R.; Mach, H.; Madurga, M.; Marroqu\'{i}n, I.; Marsh, B.; Mart\'{i}nez, M. C.; Mazzocchi, C.; Mifmmode \u{a}else \u{a}\fi{}rginean, N.; Mifmmode \u{a}else \u{a}\fi{}rginean, R.; Miernik, K.; Mihai, C.; Nácher, E.; Negret, A.; Olaizola, B.; Page, R. D.; Paulaskalas, S.; Pascu, S.; Perea, A.; Pucknell, V.; Rahkila, P.; Rapisarda, E.; Régis, J.-M.; Rotaru, F.; Rothe, S.; Sánchez-Tembleque, V.; Simpson, G.; Sotty, Ch.; Stan, L.; Stifmmode \u{a}else \u{a}\fi{}noiu, M.; Stryjczyk, M.; Tengblad, O.; Turturica, A.; Ud\'{i}as, J. M.; Van Duppen, P.; Vedia, V.; Villa, A.; Vi nals, S.; Wadsworth, R.; Walters, W. B.; Warr, N. in Phys. Rev. C (2019). 99(2) 024304.
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Optimization and characterization of the PGAI-NT instrument's Neutron Tomography set-up at MLZ. Kluge, E. J.; Stieghorst, C.; Revay, Zs.; Kudejova, P.; Jolie, J. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2019). 932 1--15.
The Prompt Gamma-ray Activation Imaging and Neutron Tomography (PGAI-NT) instrument at the PGAA facility of the Heinz Maier-Leibnitz Center (MLZ), provides a method to obtain and effectively visualize position-sensitive element abundances in samples by combining a three-dimensional extension of Prompt Gamma-ray Activation Analysis (PGAA) and Neutron Tomography (NT). Inspired by a proof-of-principle study, a cone-beam tomography set-up was designed, tested and installed. This article reports on the design of the new cone-beam tomography set-up and its optimization using neutron beam simulations and physical measurements. A new position-sensitive neutron detector with improved performance and instrument environment integration was designed, built and tested. The overall NT performance of the set-up is investigated in the course of a Quality Assessment for neutron tomography sites. Its stand-alone NT and all-in-one PGAI-NT suitability is determined.
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Fine structure of the pygmy quadrupole resonance in Sn-112,Sn-114. Tsoneva, N.; Spieker, M.; Lenske, H.; Zilges, A. in Nuclear Physics A (2019). 990 183-198.
The electric quadrupole response in Sn-112,Sn-114 isotopes is investigated by energy-density functional (EDF) and three-phonon quasiparticle-phonon model (QPM) theory with special emphasis on electric quadrupole excitations located above the first collective 2(+) state and below 5 MeV. Additional quadrupole strength clustering as a sequence of states similar to the recently observed pygmy quadrupole resonance in Sn-124 is found. The spectral distributions and transition densities of these 2(+) states show special features being compatible with oscillations of a neutron skin against the isospin-symmetric nuclear core. Furthermore, two (p, p' gamma) Doppler-shift attenuation (DSA) coincidence experiments were performed at the SONIC@HORUS setup. 2(+) states with excitation energies up to 4.2 MeV were populated in Sn-112,Sn-114. Lifetimes and branching ratios were measured allowing for the determination of E2 transition strengths to the ground state. A stringent comparison of the new data to EDF+QPM theory in Sn-112 and Sn-114 isotopes hints at the occurrence of a low-energy quadrupole mode of unique character which could be interpreted as pygmy quadrupole resonance. (C) 2019 Elsevier B.V. All rights reserved.
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Valence-shell dependence of the pygmy dipole resonance: E1 strength difference in Cr-50,Cr-54. Ries, P. C.; Pai, H.; Beck, T.; Beller, J.; Bhike, M.; Derya, V; Gayer, U.; Isaak, J.; Loeher, B.; Krishichayan,; Mertes, L.; Pietralla, N.; Romig, C.; Savran, D.; Schilling, M.; Tornow, W.; Typel, S.; Werner, V; Wilhelmy, J.; Zilges, A.; Zweidinger, M. in Phys. Rev. C (2019). 100(2)
Background: The low-lying electric dipole strength provides insights into the parameters of the nuclear equation of state via its connection with the pygmy dipole resonance and nuclear neutron skin thickness. Purpose: The aim was to complement the systematic of the pygmy dipole resonance and first study its behavior across the N = 28 neutron shell closure. Methods: Photon-scattering cross sections of states of Cr-50,Cr-54 were measured up to an excitation energy of 9.7 MeV via the nuclear resonance fluorescence method using gamma-ray beams from bremsstrahlung and Compton backscattering. Results: Transitions strengths, spin and parity quantum number, and average branching ratios for 55 excited states, 44 of which were observed for the first time, were determined. The comparison between the total observed strengths of the isotopes Cr-50,Cr-52,Cr-54 shows a significant increase above the shell closure. Conclusions: The evolution of the pygmy dipole resonance is heavily influenced by the shell structure.
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Multiple Shape Coexistence in 110,112Cd. Garrett, P. E.; Rodríguez, T. R.; Varela, A. Diaz; Green, K. L.; Bangay, J.; Finlay, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D. S.; Bildstein, V.; Colosimo, S.; Cross, D. S.; Demand, G. A.; Finlay, P.; Garnsworthy, A. B.; Grinyer, G. F.; Hackman, G.; Jigmeddorj, B.; Jolie, J.; Kulp, W. D.; Leach, K. G.; Morton, A. C.; Orce, J. N.; Pearson, C. J.; Phillips, A. A.; Radich, A. J.; Rand, E. T.; Schumaker, M. A.; Svensson, C. E.; Sumithrarachchi, C.; Triambak, S.; Warr, N.; Wong, J.; Wood, J. L.; Yates, S. W. in Phys. Rev. Lett. (2019). 123(14) 142502.
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Identification of high-spin proton configurations in ¹³⁶Ba and ¹³⁷Ba. Kaya, L.; Vogt, A.; Reiter, P.; Müller-Gatermann, C.; Gargano, A.; Coraggio, L.; Itaco, N.; Blazhev, A.; Arnswald, K.; Bazzacco, D.; Birkenbach, B.; Bracco, A.; Bruyneel, B.; Corradi, L.; Crespi, F. C. L.; de Angelis, G.; Droste, M.; Eberth, J.; Farnea, E.; Fioretto, E.; Fransen, C.; Gadea, A.; Giaz, A.; Görgen, A.; Gottardo, A.; Hadyńska-Klęk, K.; Hess, H.; Hetzenegger, R.; Hirsch, R.; John, P. R.; Jolie, J.; Jungclaus, A.; Korten, W.; Leoni, S.; Lewandowski, L.; Lunardi, S.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Mijatović, T.; Montagnoli, G.; Montanari, D.; Napoli, D.; Podolyák, Zs.; Pollarolo, G.; Recchia, F.; Rosiak, D.; Saed-Samii, N.; Şahin, E.; Siciliano, M.; Scarlassara, F.; Seidlitz, M.; Söderström, P.-A.; Stefanini, A. M.; Stezowski, O.; Szilner, S.; Szpak, B.; Ur, C.; Valiente-Dobón, J. J.; Weinert, M.; Wolf, K.; Zell, K. O. in Phys. Rev. C (2019). 99(1) 014301.
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On the imprecisions that may be induced when applying the Blaugrund approximation for the analysis of Doppler-shift attenuation lifetime measurements. Petkov, P.; Müller-Gatermann, C. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2019). 915 40 - 46.
It is shown that the Blaugrund approximation could have led to some imprecise lifetime determinations in the past which used the Doppler-shift attenuation method (DSAM). Comparison with Monte Carlo simulations of the slowing-down process show that there is not an easy way to judge using them on the reliability of old data.
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Low-lying octupole isovector excitation in ¹⁴⁴Nd. Thürauf, M.; Stoyanov, Ch.; Scheck, M.; Jentschel, M.; Bernards, C.; Blanc, A.; Cooper, N.; De France, G.; Gregor, E. T.; Henrich, C.; Hicks, S. F.; Jolie, J.; Kaleja, O.; Köster, U.; Kröll, T.; Leguillon, R.; Mutti, P.; O'Donnell, D.; Petrache, C. M.; Simpson, G. S.; Smith, J. F.; Soldner, T.; Tezgel, M.; Urban, W.; Vanhoy, J.; Werner, M.; Werner, V.; Zell, K. O.; Zerrouki, T. in Phys. Rev. C (2019). 99(1) 011304.
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Collectivity of the 2p-2h proton intruder band of ¹¹⁶Sn. Petrache, C. M.; Régis, J.-M.; Andreoiu, C.; Spieker, M.; Michelagnoli, C.; Garrett, P. E.; Astier, A.; Dupont, E.; Garcia, F.; Guo, S.; Häfner, G.; Jolie, J.; Kandzia, F.; Karayonchev, V.; Kim, Y.-H.; Knafla, L.; Köster, U.; Lv, B. F.; Marginean, N.; Mihai, C.; Mutti, P.; Ortner, K.; Porzio, C.; Prill, S.; Saed-Samii, N.; Urban, W.; Vanhoy, J. R.; Whitmore, K.; Wisniewski, J.; Yates, S. W. in Phys. Rev. C (2019). 99(2) 024303.
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Toward the limit of nuclear binding on the N=Z line: Spectroscopy of ⁹⁶Cd. Davies, P. J.; Park, J.; Grawe, H.; Wadsworth, R.; Gernhäuser, R.; Krücken, R.; Nowacki, F.; Ahn, D. S.; Ameil, F.; Baba, H.; Bäck, T.; Blank, B.; Blazhev, A.; Boutachkov, P.; Browne, F.; Čeliković, I.; Dewald, M.; Doornenbal, P.; Faestermann, T.; Fang, Y.; de France, G.; Fukuda, N.; Gengelbach, A.; Gerl, J.; Giovinazzo, J.; Go, S.; Goel, N.; Górska, M.; Gregor, E.; Hotaka, H.; Ilieva, S.; Inabe, N.; Isobe, T.; Jenkins, D. G.; Jolie, J.; Jung, H. S.; Jungclaus, A.; Kameda, D.; Kim, G. D.; Kim, Y.-K.; Kojouharov, I.; Kubo, T.; Kurz, N.; Lewitowicz, M.; Lorusso, G.; Lubos, D.; Maier, L.; Merchan, E.; Moschner, K.; Murai, D.; Naqvi, F.; Nishibata, H.; Nishimura, D.; Nishimura, S.; Nishizuka, I.; Patel, Z.; Pietralla, N.; Rajabali, M. M.; Rice, S.; Sakurai, H.; Schaffner, H.; Shimizu, Y.; Sinclair, L. F.; Söderström, P.-A.; Steiger, K.; Sumikama, T.; Suzuki, H.; Takeda, H.; Taprogge, J.; Thöle, P.; Valder, S.; Wang, Z.; Warr, N.; Watanabe, H.; Werner, V.; Wu, J.; Xu, Z. Y.; Yagi, A.; Yoshinaga, K.; Zhu, Y. in Phys. Rev. C (2019). 99(2) 021302.
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Lifetimes in ²¹¹At and their implications for the nuclear structure above ²⁰⁸Pb. Karayonchev, V.; Blazhev, A.; Esmaylzadeh, A.; Jolie, J.; Dannhoff, M.; Diel, F.; Dunkel, F.; Fransen, C.; Gerhard, L. M.; Gerst, R.-B.; Knafla, L.; Kornwebel, L.; Müller-Gatermann, C.; Régis, J.-M.; Warr, N.; Zell, K. O.; Stoyanova, M.; Van Isacker, P. in Phys. Rev. C (2019). 99(2) 024326.
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A new dedicated plunger device for the GALILEO γ-ray detector array. Müller-Gatermann, C.; von Spee, F.; Goasduff, A.; Bazzacco, D.; Beckers, M.; Braunroth, T.; Boso, A.; Cocconi, P.; de Angelis, G.; Dewald, A.; Fransen, C.; Goldkuhle, A.; Gottardo, A.; Gozzelino, A.; Hadyńska-Klęk, K.; Jawroski, G.; John, P.R.; Jolie, J.; Lenzi, S.M.; Litzinger, J.; Menegazzo, R.; Mengoni, D.; Napoli, D.R.; Recchia, F.; Siciliano, M.; Testov, D.; Thiel, S.; Valiente-Dobón, J.J.; Zell, K.O. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2019). 920 95--99.
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Improvements in the measurement of small 14CO2 samples at {CologneAMS}. Stolz, A.; Dewald, A.; Heinze, S.; Altenkirch, R.; Hackenberg, G.; Herb, S.; Müller-Gatermann, C.; Schiffer, M.; Zitzer, G.; Wotte, A.; Rethemeyer, J.; Dunai, T. in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms (2019). 439 70--75.
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Microscopic structure of coexisting 0⁺ states in ⁶⁸Ni probed via two-neutron transfer. Flavigny, F.; Elseviers, J.; Andreyev, A. N.; Bauer, C.; Bildstein, V.; Blazhev, A.; Brown, B. A.; De Witte, H.; Diriken, J.; Fedosseev, V. N.; Franchoo, S.; Gernhäuser, R.; Huyse, M.; Ilieva, S.; Klupp, S.; Kröll, Th.; Lutter, R.; Marsh, B. A.; Mücher, D.; Nowak, K.; Otsuka, T.; Pakarinen, J.; Patronis, N.; Raabe, R.; Recchia, F.; Reiter, P.; Roger, T.; Sambi, S.; Seidlitz, M.; Seliverstov, M. D.; Siebeck, B.; Tsunoda, Y.; Van Duppen, P.; Vermeulen, M.; Von Schmid, M.; Voulot, D.; Warr, N.; Wenander, F.; Wimmer, K. in Phys. Rev. C (2019). 99(5) 054332.
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Pulse-Shape Analysis and position resolution in highly segmented HPGe AGATA detectors. Lewandowski, L.; Reiter, P.; Birkenbach, B.; Bruyneel, B.; Clement, E.; Eberth, J.; Hess, H.; Michelagnoli, C.; Li, H.; Perez-Vidal, R. M.; Zielinska, M. in The European Physical Journal A (2019). 55(5) 81.
The performance of the Pulse-Shape Analysis (PSA) in AGATA HPGe detectors was investigated and improved employing a {\\($}{\backslash}gamma{\$\)}\($\gamma$\)-ray source measurement based on {\\($} e^{\{}+{\}}e^{\{}-{\}}{\$\)}e+e-annihilation radiation after decays of 22Na by {\\($} {\backslash}beta^{\{}+{\}}{\$\)}\($\beta$\)+decay. The first interaction positions of the two 511keV {\\($}{\backslash}gamma{\$\)}\($\gamma$\)rays were determined and the connecting line of these two positions was compared to the known source position as a measure for the PSA performance. The position resolution and its dependence on the PSA parameters were investigated by varying most relevant input quantities: the charge carrier mobility of the holes, the response of the employed measuring electronics especially the preamplifier rise time. The relative statistical weight of charge signals and transient signals was scrutinized. The optimal distance metric of the grid-search algorithm and its impact on the position resolution were determined.
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Shape coexistence in 178Hg. Müller-Gatermann, C.; Dewald, A.; Fransen, C.; Auranen, K.; Badran, H.; Beckers, M.; Blazhev, A.; Braunroth, T.; Cullen, D. M.; Fruet, G.; Goldkuhle, A.; Grahn, T.; Greenlees, P. T.; Herzáifmmode \check{n}else \v{n}\fi{}, A.; Jakobsson, U.; Jenkins, D.; Jolie, J.; Julin, R.; Juutinen, S.; Konki, J.; Leino, M.; Litzinger, J.; Nomura, K.; Pakarinen, J.; Peura, P.; Procter, M. G.; Rahkila, P.; Ruotsalainen, P.; Sandzelius, M.; Sarén, J.; Scholey, C.; Sorri, J.; Stolze, S.; Taylor, M. J.; Uusitalo, J.; Zell, K. O. in Phys. Rev. C (2019). 99(5) 054325.
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Probing isospin symmetry in the (⁵⁰Fe, ⁵⁰Mn, ⁵⁰Cr) isobaric triplet via electromagnetic transition rates. Giles, M. M.; Nara Singh, B. S.; Barber, L.; Cullen, D. M.; Mallaburn, M. J.; Beckers, M.; Blazhev, A.; Braunroth, T.; Dewald, A.; Fransen, C.; Goldkuhle, A.; Jolie, J.; Mammes, F.; Müller-Gatermann, C.; Wölk, D.; Zell, K. O.; Lenzi, S. M.; Poves, A. in Phys. Rev. C (2019). 99(4) 044317.
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Lifetime measurement of excited states in ⁴⁶Ti. Goldkuhle, A.; Fransen, C.; Dewald, A.; Arnswald, K.; Bast, M.; Beckers, M.; Blazhev, A.; Braunroth, T.; Hackenberg, G.; Häfner, G.; Litzinger, J.; Jolie, J.; Müller-Gatermann, C.; von Spee, F.; Warr, N.; Werner, D.; Zell, K. O. in The European Physical Journal A (2019). 55(4) 53.
The level lifetimes of the yrast 21+, 41+ and 61+ states and an upper limit of the lifetime of the 81+ state in 46Ti have been measured with high accuracy exploiting the recoil distance Doppler-shift method (RDDS) and using {\\($}{\backslash}gamma{\backslash}gamma{\$\)}\($\gamma$\)\($\gamma$\)coincidences. The nuclei were populated by the fusion evaporation reaction 40Ca(9Be, 2p1n)46Ti at a beam energy of {\\($}E=33{\$\)}E=33MeV at the FN tandem accelerator of the University of Cologne, Germany. Lifetimes were extracted using the established differential decay curve method (DDCM).
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Decay properties of the 3⁻₁ level in ⁹⁶Mo. Gregor, E T; Arsenyev, N N; Scheck, M; Shneidman, T M; Thürauf, M; Bernards, C; Blanc, A; Chapman, R; Drouet, F; Dzhioev, A A; de France, G; Jentschel, M; Jolie, J; Keatings, J M; Kröll, Th; Köster, U; Leguillon, R; Mashtakov, K R; Mutti, P; O'Donnell, D; Petrache, C M; Simpson, G S; Sinclair, J; Smith, J F; Soldner, T; Spagnoletti, P; Sushkov, A V; Urban, W; Vancraeyenest, A; Vanhoy, J R; Werner, V; Zell, K O; Zielinska, M in Journal of Physics G: Nuclear and Particle Physics (2019). 46(7) 075101.
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Lifetime of the 15/2⁻₁ state in ¹³⁵Te. Simpson, G; Regis, J M; Bettermann, L; Genevey, J; Jolie, J; Köster, U; Materna, T; Malkiewicz, T; Muraz, J-F; Pinston, J A; Roussiere, B; Thiamova, G in Journal of Physics G: Nuclear and Particle Physics (2019). 46(6) 065108.
The lifetime of the state of 135Te has been measured to be τ = 809(22) ps, corresponding to a reduced transition rate of =6.6(2) W.u. The experiment was performed at the focal point of the Lohengrin spectrometer and μs-delayed γ rays from mass-selected A = 135 ions were detected by four LaBr3(Ce) scintillators. This allowed the fast-timing technique to be used to access lifetimes in the 10s-of-ps to ns time region. The value is typical of a vibrational transition, despite 135Te possessing only one valence neutron and two valence protons. Shell model calculations performed with the state-of-the-art effective interaction predict a B(E2) value close to the experimental one and show that contributions from the π(g 7/2, d 5/2)νf 7/2 couplings are coherent.
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High-resolution study of the Gamow-Teller (GT-) strength in the ⁶⁴Zn(³He,t)⁶⁴Ga reaction. Diel, F.; Fujita, Y.; Fujita, H.; Cappuzzello, F.; Ganioğlu, E.; Grewe, E.-W.; Hashimoto, T.; Hatanaka, K.; Honma, M.; Itoh, T.; Jolie, J.; Liu, Bin; Otsuka, T.; Takahisa, K.; Susoy, G.; Rubio, B.; Tamii, A. in Phys. R