Optimization for energy response characteristics of plastic scintillators based on genetic algorithm

Abstract

To address the problem that the energy response of the plastic scintillator detector is very low in the low energy range, this paper proposes a method to optimize the energy response characteristics by combining the CaWO4 energy compensation layer and the genetic algorithm. First, the energy deposition of X/γ rays in a plastic scintillator with a CaWO4 energy compensation layer is modeled and simulated using MCNP software; then, the thickness and hollow radius of the compensation layer are optimized by using genetic algorithm to run this simulation program. The results show that after adding a CaWO4 compensation layer with a thickness of 45 µm and a hollow radius of 1 cm at the front of the plastic scintillator, its energy response characteristics are consistent in the range of 50 keV to 1.5 MeV, which meets the requirement of IEC 61584:2001 for the energy response coefficient less than ±30%. The maximum deviation of the energy response coefficient at the energy point of 0.662 MeV is reduced from 44% to 13%.