[2I13-17] 新手法・新技術開発

[2I13] Investigating effects of coaxial HPGe detector structure on the measurement of LCS gamma-ray beam

*Mohamed Omer¹, Toshiyuki Shizuma^1,2, Mitsuo Koizumi¹, Yoshitaka Taira³, Heishun Zen⁴, Ryoichi Hajima^1,2 (1. JAEA, 2. QST, 3. UVSOR, IMS, 4. IAE, Kyoto Univ.)

キーワード：LCS gamma-rays, Coaxial HPGe detector, Detection efficiency

Coaxial high-purity germanium detectors are essential components of high-resolution gamma-ray spectrometers. Indeed, these detectors come in various dimensions with different internal structures. Particularly when the measured gamma-rays are in the form of a directed beam, the detector’s internal structure may affect the measured gamma-ray spectra significantly. Here we investigate the effect of the internal structure of two different coaxial HPGe detectors using 5.5 MeV gamma-rays generated by laser Compton scattering at the UVSOR III facility. The gamma-ray beam hit the detectors in two configurations, axial and nonaxial. We found that the nonaxial configuration provides higher efficiency and lower background than the axial configuration, which was confirmed using Monte Carlo simulations. Our results provide improvements in the measurement of gamma-ray beams.