Modeling of Signal Generation in Gamma-Ray Detectors

In Nuclear Physics experiments, methods and codes are needed to model the electrical signals generated by the gamma ray detector arrays to the higher precision required by new and/or upcoming gamma ray detectors. Localizing the gamma ray interaction is an inverse problem, and the spatial precision with which it can be solved is critically dependent on the accuracy with which the corresponding signals can be simulated. This accuracy is affected by many factors, two of which are the mobility of the holes (the mobility of the electrons is well understood) and the accumulation of charge at the faces of the crystal. This project will develop simulation capabilities required to address these two factors. Phase I will: (1) develop a prototype code for improving the calculation of hole mobility in the simulated signal generation; and (2) determine the cause of, and properly take into account, the charge accumulation at the front and back crystal ends in the simulated signal generation. Commercial Applications and other Benefits as described by the awardee: Both the US and the EU are currently developing next generation gamma ray detector arrays, and both efforts should be interested in the improved signal modeling.