Geant4-based multiphysics simulation toolkit for analysis of radiation detector performance

摘要

Often only a single physical process or component is investigated in the simulation of radiation detector systems. Theresults are then considered to be representative of what is expected in the correlating physical experiment. Althoughsingular assessments may serve as a good estimate, the overall performance of a radiation detector system depends onseveral physical processes and the performance of all components within the system. Our Geant4-based multiphysicssimulation toolkit couples radiation transport with optical photon processes, providing simulations of radiation detectorsystems components from the scintillator through the photocathode of the photodetector. Work to incorporate the backenddetector components, including the complete photodetector and subsequent electronics (e.g., amplifiers, digitizers), isunderway.Geant4 is used to model the radiation transport and optical photon processes that occur in the front-end detector systemcomponents when exposed to a chosen source. These components include the scintillator, detector housing, opticalcoupling to the photodetector, and photocathode of the photodetector. Characteristics of several detector systems that havebeen studied include time response; pulse height spectra; number of photoelectrons per MeV; detector efficiency versusincident quanta energy; and effects on detector response due to change in geometries, materials, and reflectivity.Comparison of these characteristics by means of this toolkit enables the selection of the optimal individual components;thus, it is possible to specify the radiation detector system best suited to meet the requirements of any physical experiment.