Experimental verification of off-axis polarimetry with cadmium zinc telluride detectors of AstroSat-CZT Imager

The cadmium zinc telluride imager (CZTI) on board AstroSat consists of an array a large number pixelated (CZT) detectors capable measuring the polarization incident hard x-rays. measurement capability CZTI for on-axis sources was experimentally confirmed before launch. has yielded tantalizing results x-ray Crab nebula and pulsar in energy range 100 to 380 keV. also contributed prompt emission several gamma-ray bursts (GRBs). However, measurements off-axis such as GRBs are challenging. It is vital calibrate sensitivity enhance credence measurements. In this context, we report verification polarimetric CZT through controlled experiments carried out with detector similar that used extensive Geant4 simulations experimental setup. Our current show can be measure bright angles up ∼60 deg. at incidence between 45 deg 60 deg, there might some systematic effects need taken into account when interpreting measured fraction.