X-ray Detection Efficiency Characteristics of CsI(Na) and ST401 Double Layer Crystals using Monte Carlo Simulation Method

Abstract

We investigated the soft X-ray detection efficiency of CsI(Na) and ST401 double crystals using Monte Carlo method when the CsI(Na) thickness is 1 μm, 3 μm, 5 μm, 7 μm, 9 μm respectively. The simulation results reveal that the detection efficiency of CsI(Na) and ST401 and their ratios increase as the CsI(Na) crystal thickeness increased, and the CsI(Na) crystal with 9μm thickness absorbs mostly more photons than one order of magnitude compared to ST401 plastic scintillator under 1-6 KeV X-ray point source energy stimulated. But when the X-ray point source energy is in the range of 6-10 KeV, the photons absorbed by the ST401 plastic scintillator are very close to those of CsI(Na) crystal absorbed with the incident photon energy increasing.