Explicit Modeling of Timing Characteristics in Compton Camera Simulation with Geant4

Abstract

Timing characteristics are usually ignored in Compton camera simulations, resulting in large errors in the estimation of imaging sensitivity and less but still significant errors in the estimation of imaging resolution. In the present study, the accuracy of Compton camera simulation was improved by explicitly modeling the timing characteristics of a Compton camera including the randomness of photon emission time, detector time resolution, detector dead time, and coincidence window. The results were very encouraging. The discrepancies of imaging sensitivities, between simulation and experiment, were reduced to an insignificant level. The imaging resolutions were also in a good agreement, i.e., < 1 mm FWHM of difference, after explicitly modeling the timing characteristics. The results of the present study clearly show the importance of timing characteristics in Compton camera simulations.