Neutron Flux Measurement Using a Fast-Neutron Scintillation Detector with High Temporal Resolution on the Large Helical Device
Neutron Flux Measurement Using a Fast-Neutron Scintillation Detector with High Temporal Resolution on the Large Helical Device
复制标题
在大型螺旋装置上使用具有高时间分辨率的快中子闪烁探测器进行中子通量测量
DOI：
10.1585/pfr.13.3402068
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发表时间：
2018
影响因子：
0.8
通讯作者：
T. Nishitani
中科院分区：
文献类型：
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作者：
K. Ogawa;M. Isobe;Hiroki Kawase;T. Nishitani
为了获得磁流体动力学（MHD）不稳定性引起的中子发射率的快速变化，在大螺旋装置（LHD）上用一种称为中子涨落（NF）的快中子闪烁探测器在电流模式下对中子通量进行了高时间分辨率的测量。该探测器的时间响应可达5微秒。我们检查了PMT内部中子/伽马射线引起的不需要的信号水平。与预期的闪烁信号的强度相比，不需要的信号的强度小得可以忽略。在MHD静放电中，NF信号与中子通量监测器测量的总中子发射率呈线性关系。用中子通量谱观察到中性束加热LHD等离子体中激发的MHD模式爆发引起的中子通量的快速下降。我们发现中子通量在2 ms内迅速下降。
To obtain rapid change of the neutron emission rate caused by magnetohydrodynamic (MHD) instabilities, measurements of the neutron flux with the high temporal resolution are made on the Large Helical Device (LHD) with a fast-neutron scintillation detector called neutron fluctuation (NF) operated in current modes. The time response of this detector is up to 5 microseconds. We checked the unwanted signal level caused by neutrons/gamma-rays inside the PMT. The intensity of the unwanted signal was negligibly small compared with the intensity of the scintillation signal as expected. The signal of NF has linear dependence with total neutron emission rate measured by neutron flux monitor in MHD quiet discharges. Rapid decreases of the neutron flux associated with bursting MHD modes excited in a neutral-beam-heated LHD plasma are observed with NF. We found that the neutron flux rapidly decreases within 2 ms.