Analytic Study of Prompt and Delayed Gamma Distributions

Using binomial statistics and direct convolution integral, formulas are derived for delayed and antidelayed gamma distributions involving scintillation detectors. T½ of a nuclear state is extracted from the best fitting with experimental delay distribution using χ2-deviation criteria. For semiconductor detectors, a direct method is presented to compute T½ from a measure of the time interval between maxima of the delay curve and the prompt one of Gaussian shape. The different methods of analysis of short lifetimes are tested through coincidence experiments applying scintillation and planar Ge(Li) detectors.