A wide measurement range for a neutron flux monitoring (NFM) system is developed in the Experimental Advanced Superconducting Tokamak (EAST) for fusion neutron yield measurement, comprising an 3He proportional counter, a 235U fission chamber (FC), and a wide dynamic range signal-processing circuit. Two high-sensitivity 3He detectors operate in counting mode, which is suitable for low neutron yield (Yn) conditions with ohmic and radio-frequency heating of plasma. Two other FCs are adapted with newly developed digitizers, operating in counting and campbelling modes to satisfy the conditions of wide dynamic range measurement required by neutral beam injection (NBI) experiment. The anti-magnetic-field interference of the FC is examined using two permanent magnets, whose efficiency are calibrated with 2.46 MeV neutrons produced by a Van de Graaff accelerator. Furthermore, the NFM system is implemented in-situ calibration with a 252Cf neutron source and a remote handling. As a routine diagnostic, the NFM system is successful obtaining the fusion neutron yield for ion cyclotron resonance heating (ICRH) and NBI heating performance evaluation in EAST plasma experiment.

中文翻译：

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EAST大范围中子通量监测系统的开发

实验先进超导托卡马克 (EAST) 开发了用于聚变中子产额测量的中子通量监测 (NFM) 系统的宽测量范围，包括 3He 正比计数器、235U 裂变室 (FC) 和宽动态范围信号-处理电路。两个高灵敏度 3He 探测器以计数模式运行，适用于低中子产率 (Yn) 条件，对等离子体进行欧姆加热和射频加热。另外两个 FC 配备了新开发的数字化仪，在计数和坎贝尔模式下运行，以满足中性束注入 (NBI) 实验所需的宽动态范围测量条件。FC 的抗磁场干扰使用两个永磁体进行检查，其效率校准为 2。范德格拉夫加速器产生的 46 MeV 中子。此外，NFM 系统采用 252Cf 中子源和远程处理进行原位校准。作为常规诊断，NFM 系统成功获得了用于离子回旋共振加热 (ICRH) 和 EAST 等离子体实验中 NBI 加热性能评估的聚变中子产额。