Development of an Electron-Tracking Compton Camera using CF sub(4 gas at high pressure for improved detection efficiency)

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2011-02, Vol.628 (1), p.150-153
• Main Authors: Takahashi, Michiaki, Kabuki, Shigeto, Hattori, Kaori, Higashi, Naoki, Iwaki, Satoru, Kubo, Hidetoshi, Kurosawa, Shunsuke, Miuchi, Kentaro, Nakamura, Kiseki, Nishimura, Hironobu, Parker, Joseph D, Sawano, Tatsuya, Takada, Atsushi, Tanimori, Toru, Taniue, Kojiro, Ueno, Kazuki
• Format: Article
• Language: English
• Subjects: Accelerators; Angular resolution; Arrays; Astronomy; Cameras; Chambers; Gain; Optimization
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2010.06.305

We have developed an Electron-Tracking Compton Camera (ETCC) for medical imaging and MeV gamma-ray astronomy. The ETCC consists of a gaseous Time Projection Chamber ( mu -TPC) and pixel scintillator arrays. To improve the detection efficiency, we have optimized the gas mixture in the mu -TPC and operated the ETCC at high pressure. Basic characteristics such as the gas gain, drift velocity, energy resolution, and position resolution of the mu -TPC were examined, and using this optimization, both the efficiency and the angular resolution of the ETCC were measured. We achieved a steady gas gain of [not, vert, similar]20,000 in Ar/CF sub(4/isoC) sub(4)H sub(10 (54:40:6) at 1.4 atm. The diffusion constant in Ar/CF) sub(4)/isoC sub(4H) sub(1)0 (54:40:6) at 1.4 atm was [not, vert, similar]2 times better than in Ar/C sub(2H) sub(6) (90:10) at 1 atm. The efficiency in Ar/CF sub(4/isoC) sub(4)H sub(10 (54:40:6) at 1.4 atm was also [not, vert, similar]2 times higher than in Ar/C) sub(2)H sub(6 (90:10) at 1 atm.)