Optimization of design for X-ray imaging gas polarimeter using computer simulation

We have been developing the gas imaging polarimeter sensitive to the energy range above 10 keV. To optimize the design of the polarimeter, computer simulation code is necessary. So we have developed the computer simulation applying modified Electron Gamma-ray Simulation Version.4 (EGS4) code and GARFIELD code. To investigate the performance of the simulation code, we compared the data for a gas imaging X-ray polarimeter developed by Costa et al. with the results from the simulation code. As the result, we confirmed that the computer simulation well reproduces the performance of the real polarimeter. Moreover, we estimated the optimal parameters of the gas imaging polarimeter sensitive to the energy range above 10 keV using the computer simulation code. From the results, it was recognized that gas mixture of argon-DME with 3∼4 cm gas depth is optimal at 1 atm.