Development of hard X-ray polarimeter for γ-ray bursts Original Research Article

The radiation mechanism of gamma-ray bursts (GRBs) is one of the most interesting topics in the field of astrophysics. According to the fireball model, the γ-rays from GRBs should be much polarized. So we have been developing a Compton scattering type hard X-ray polarimeter for GRBs using segmented scintillators and multianode photomultipliers. We carried out basic experiments and computer simulations to investigate the basic performance. As the results, it was recognized that the designed polarimeter can detect the polarization of hard X-rays from GRBs with both the flux 10 times more than that of Crab nebula and the duration of 10 s if the hard X-rays are 8.6% polarized.