Study of the Polarimetric Performance of a Si/CdTe Semiconductor Compton Camera for the Hitomi Satellite

Abstract

Gamma-ray polarization offers a unique probes into the geometry of the gamma-ray emission process in celestial objects. The Soft Gamma-ray Detector (SGD) onboard the X-ray observatory Hitomi is a Si/CdTe Compton camera and is expected to be an excellent polarimeter, as well as a highly sensitive spectrometer due to its good angular coverage and resolution for Compton scattering. A beam test of the final-prototype for the SGD Compton camera was conducted to demonstrate its polarimetric capability and to verify and calibrate the Monte Carlo simulation of the instrument. The modulation factor of the SGD prototype camera, evaluated for the inner and outer parts of the CdTe sensors as absorbers, was measured to be 0.649--0.701 (inner part) and 0.637--0.653 (outer part) at 122.2 keV and 0.610--0.651 (inner part) and 0.564--0.592 (outer part) at 194.5 keV at varying polarization angles with respect to the detector. This indicates that the relative systematic uncertainty of the modulation factor is as small as ~3%.

arXiv commentaccepted for publication in NIMA

References in corpus (13)

• Recent Progress in CdTe and CdZnTe Detectors
• Detection of Gamma-Ray Polarization in Prompt Emission of GRB 100826A
• Polarization of the Crab pulsar and nebula as observed by the Integral/IBIS telescope
• Magnetic Structures in Gamma-Ray Burst Jets Probed by Gamma-Ray Polarization
• The ASTRO-H X-ray Observatory
• The polarized Gamma-Ray Burst GRB 061122
• The Si/CdTe semiconductor Compton camera of the ASTRO-H Soft Gamma-ray Detector (SGD)
• Soft Gamma-ray Detector for the ASTRO-H Mission
• The ASTRO-H X-ray Astronomy Satellite
• Wide band X-ray Imager (WXI) and Soft Gamma-ray Detector (SGD) for the NeXT Mission
• A recent change in the optical and γ-ray polarization of the Crab nebula and pulsar
• The first demonstration of the concept of "narrow-FOV Si/CdTe semiconductor Compton camera"
• Gamma-ray Polarimetry

Cited by in corpus (5)

• Detection of polarized gamma-ray emission from the Crab nebula with Hitomi Soft Gamma-ray Detector
• An application of a Si/CdTe Compton camera for the polarization measurement of hard x-rays from highly charged heavy ions
• Imaging Polarimeter for a Sub-MeV Gamma-Ray All-Sky Survey using an Electron-Tracking Compton Camera
• Demonstration of nuclear gamma-ray polarimetry based on a multi-layer CdTe Compton Camera
• Compton Telescopes for Gamma-ray Astrophysics