An ionization chamber developed for the facility of heavy ions therapy at IMP

作者：Hu Zhengguo^*; Xu Zhiguo; Xiao Guoqing; Sun Zhiyu; Xu Hushan; Zhang Xueheng; Mao Ruishi; Zhang Hongbin; Huang Tianheng; Fu Fen; Tang Bin; Tu Xiaolin; Wang Meng; Xiao Zhigang; Wang Jiansong; Li Qiang; Guo Zhongyan

来源：Nuclear Techniques, 2007, 30(2): 139-142.

An ionization chamber (IC) with a sensitive area of 250mm × 250 mm was developed for the Institute of Modern Physics (IMP) heavy ion therapy facility. The gap was 10 mm between the anode and the cathode. A good plateau was seen in a large voltage range from 900V to 3000V when the IC was operated at (85.0 minus or plus 0.2) kPa with P10 (10% CH4+90% At) as flowing gas. By putting the different thicknesses of polymethyl methacrylate (PMMA) in front of the IC, the Bragg curve for the beam in PMMA was measured by the IC. During the test, the voltage of 2300 V was applied to the anode of the IC. The measured Bragg peak for 75 MeV/u 12C6+ ions in the PMMA was located at 13.73 mm and the FWHM was 0.19mm.

• 出版日期2007