Study of the factors effecting the appearance of sum peak in gamma ray spectra

The factors which affect the appearance of the sum peak in γ-rays spectra for the elements of cascade decay have been studied, the calculation of the correction factor of the sum peak has shown that the sum peak has its affect on the efficiency of the full energy photo peak, mainly at low energies where at which the correction factor is increased. Because of high efficiency of scintillation detector NaI(TI) has been used for detection, (it is known that efficiency increases with increasing the crystal size). For this reason, two crystals (2''x2''), (3''x3'') have been used. Some experiments have been operated for calibration of the electronics system. The calibration elements which have been used for this purpose are (Bi-207, Cs-137, Mn-54, Na-22, Co-60, Y-88). Some points have been suggested in order to reduce the inevitable effect of the sum peak on the full energy photo peak, although these suggestions will not abosultely elminate this effect. 28 tabs.; 42 figs.; 57 refs