High repetition rate neutron flux array using digital-signal processing and scintillators for study of high performance plasma at JT-60U

JT-60Uの高性能プラズマ研究のためのデジタル信号処理とシンチレータ検出器を用いた高計数率中性子分布計測システム

篠原 孝司; 奥地 俊夫*; 石川 正男; 馬場 護*; 糸賀 俊朗*

Shinohara, Koji; Okuji, Toshio*; Ishikawa, Masao; Baba, Mamoru*; Itoga, Toshiro*

Neutron brings the information about the energetic ion population. Radial neutron collimator system is used to measure a line-integrated neutron emission profile in JT-60U tokamak. An analog neutron- pulse shape discrimination circuit was used to measure neutron flux from the DD reaction. The maximum count rate of the analog circuit is limited up to 110 counts/s. Aiming at increasing the count rate, a digital signal processing method for neutron- signal discrimination has been adopted to our collimator system. This includes a modification of hardware, a development of software, and a calibration. Due to this update, the radial neutron collimator system can output the information about the temporal evolution of neutron emission rate, temporal evolution of ray emission rate.