Insights into the Operation of the Clover Detector: Detector Response to High Energy Gamma-rays and Phenomenological Modeling

We have performed both experimental and theoretical studies with the clover detectors. Gamma-rays from standard radioactive sources and the beta decay of a radioactive 11Be beam have been used to investigate the response of seven escape suppressed TIGRESS detectors up to an energy of 8 MeV. Measurements of absolute efficiency, addback factor, fold distribution, peak-to-total ratio and ratio of escape peak area to full energy peak area have been performed. Comparisons have been made between TIGRESS and similar composite detectors. We have also performed comparison of background characteristics of normal HPGe and clover detectors using both active and passive shielding. Considering the scattering and absorption of gamma-rays, a simple model based on probability flow arguments, has been developed for understanding the operation of the clover detector. Using experimental data, we have calculated the peak-to-total ratio for energy region where experimental information about the ratio is absent. Our predictions are found to be in agreement with the experimental data. The present formalism is able to describe various clover-type detectors along with cluster detector and SPI spectrometer.