A study of an asymmetric Compton suppression spectrometer by Monte Carlo simulation

The geometrical parameters which affect the suppression factor for a HpGe-NaI(Tl) Compton suppression spectrometer are studied by Monte Carlo simulation. The simulation parameters are designed for comparison of the experimental results of the specified Compton suppression spectrometer with a HpGe detector as the central detector. The simulated results are in coincidence with the experimental results. The optimal position of the HpGe detector within the shielding of the NaI(Tl) detector in two kinds of asymmetry Compton suppression spectrometer, which we named L(T)-shape and L(C)-shape is studied. The optimized suppression position is consistent with the previous simulated results, that the front face of the central detector is about at 34–45 length of the shielding along the hole dimension. Further simulation indicates that the suppression factor is quickly saturated by increasing the shielding thickness along the dimension perpendicular to the hole for the central detector.