Evaluation of Timepix3 with a 1 mm thick silicon sensor as a Compton imaging polarimeter in the hard X-ray band

Abstract The present work demonstrates the usage of a Timepix3 with a 1 mm thick silicon sensor as a scattering polarimeter with simultaneous Compton-camera imaging. For this purpose, laboratory experiments were designed where the detector was placed at different scattering angles with respect to a plastic target that is irradiated with X-rays from a Hamamatsu microfocus tube (tube voltage 75 kV, tube current 60 µA). Photons scattered in the target at 90 ∘ are almost 100 % linearly polarized. Measurements in an energy range of 32.5–67.5 keV showed modulation factors above 70 %. Simulations of 100 % linearly polarized beams showed modulation factors μ 100 > 77 % in an energy range of 45–80 keV. The efficiency of detection has a maximum above 0.13 % at 45–50 keV. We implemented the origin ensemble with resolution recovery (OE-RR) algorithm for Compton camera imaging. The full width at half maximum (FWHM) of the image of 16–21 ∘ was achieved.