Development of a high-temporal resolution neutron flux measurement system for the HL-2M tokamak. (1st July 2022)

• Record Type: Journal Article
• Authors: Zhang, Jie; Zhang, Yipo; Zhang, Jinglong; Zhou, Jianhang; Zhan, Xuwen; Wen, Zuowei; Cheng, Shikui; Zhu, Yuxuan; Yuan, Guoliang; Liu, Yuhang; Yang, Qiulei; Chen, Wei; Shi, Zhongbing; Liu, Yi; Xu, Min
• Is Part Of: Journal of instrumentation. Volume 17:Number 7(2022)
• Publication Date: 2022-07-01
• Subjects: Nuclear instruments and methods for hot plasma diagnostics -- Neutron detectors (cold, thermal, fast neutrons) -- Simulation methods and programs; Scientific apparatus and instruments -- Periodicals; 502.84
• DOI: 10.1088/1748-0221/17/07/P07027
• Languages: English
• ISSNs: 1748-0221

Abstract

Abstract: To enhance the understanding of the physics of energetic ions in fusion plasma, a high-temporal resolution neutron flux measurement (HTRNFM) system, which is equipped with a fast-neutron scintillation detector embedded with ZnS:Ag phosphor, has been developed for the HL-2M tokamak. It has a temporal resolution of 10 μs during conventional operations. Its dynamic range is sufficiently wide for neutron flux measurements by adopting the combination use of the scalar mode and the Campbell mode. Based on the Monte Carlo calculations, the applicable count rate ranges of both the scalar mode and the Campbell mode are respectively 0.1–10 Mcps and 10–200 Mcps. The performance validation of the HTRNFM system has been performed by neutron flux measurements in magnetohydrodynamic (MHD) quiet plasmas in the HL-2A tokamak. In another plasma with abundant MHD instabilities, both the continuous neutron flux decreases and the rapid neutron flux decreases caused by different MHD instabilities are observed in a more detailed manner for the first time with the HTRNFM system than with other neutron flux measurement (NFM) systems that have a lower temporal resolution of 1 ms. The HTRNFM system will serve as a powerful diagnostic tool for research on energetic ion confinement quality in the HL-2M tokamak.