A STUDY OF AN ASYMMETRIC COMPTON SUPPRESSION SPECTROMETER BY MONTE-CARLO SIMULATION

The geometrical parameters which affect the suppression factor for a H pGe-NaI(T1) Compton suppression spectrometer are studied by Monte Carl o simulation. The simulation parameters are designed for comparison of the experimental results of the specified Compton suppression spectro meter with a HpGe detector as the central detector. The simulated resu lts are in coincidence with the experimental results. The optimal posi tion of the HpGe detector within the shielding of the NaI(TI) 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 f ront face of the central detector is about at 3/4 - 4/5 length of the shielding along the hole dimension. Further simulation indicates that the suppression factor is quickly saturated by increasing the shieldin g thickness along the dimension perpendicular to the hole for the cent ral detector.