An application of a Si/CdTe Compton camera for the polarization measurement of hard x rays from highly charged heavy ions

The methods to measure the polarization of x-rays from highly charged heavy ions with a significantly higher accuracy than existing technology is needed explore relativistic and quantum electrodynamics (QED) effects including Breit interaction. We developed Electron Beam Ion Trap Compton Camera (EBIT-CC), new polarimeter pixelated multi-layer silicon cadmium telluride counters. EBIT-CC detects three-dimensional position scattering photoelectric absorption, thus degree incoming can be evaluated. attached on Tokyo (Tokyo-EBIT) in University Electro-Communications. An experiment was performed evaluate its polarimetric capability through an observation radiative recombination emitted krypton ions, which were generated by Tokyo-EBIT. camera calibrated for 75 keV x-rays. event reconstruction selection procedures applied them every registered event. As result, we successfully obtained absolute uncertainty 0.02. This small enough probe difference between zero-frequency approximation full-frequency-dependent calculation interaction, expected dielectronic ions.