Fit and integration

      The interesting results of the quantitative analysis of spectra are position, volume and shape of the observed peaks. The analysis must comprise a proper description of the background. Since the background has a more global structure, whereas the peaks in a gamma spectrum are local structures, the former can be approximated by a polynom, usually of second degree. On the contrary, particle spectra have very broad peaks. Therefore it is necessary to use a more physical description of the background which is provided by an exponential term besides the polynom. This background function may be useful in the upper part of a Ge-detector's spectrum, too since the exponential term reproduces approximately the detector's efficiency.

TV offers three methods for the analysis of spectra as there are integration, peaksearch and fit, whereat two different functions to fit the peaks and two different functions to approximate the background can be used. The methods are explained in the following sections while the definitions are given in appendix D on page .