Neutron flux distributions in the Large Helical Device torus hall evaluated by an imaging plate technique in the first campaign of the deuterium plasma experiment
Neutron flux distributions in the Large Helical Device torus hall evaluated by an imaging plate technique in the first campaign of the deuterium plasma experiment
复制标题
在氘等离子体实验的第一次活动中通过成像板技术评估大型螺旋装置环面大厅中的中子通量分布
DOI：
10.1088/1741-4326/ab3d14
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发表时间：
2019
期刊：
影响因子：
3.3
通讯作者：
M. Osakabe
中科院分区：
文献类型：
--
作者：
Makoto Kobayashi;Tomoyo Tanaka;T. Nishitani;K. Ogawa;M. Isobe;G. Motojima;A. Kato;S. Yoshihashi;M. Osakabe
利用成像板和高纯锗探测器测量的活化箔法，在大型螺旋装置（LHD）上首次对大型聚变装置环形大厅内热中子、超热中子和快中子的总体通量分布进行了实验研究。事实证明，热中子被放置在LHD下面的硼化聚乙烯块有效地吸收。这应可减低地面的辐射量，并有助维持一个良好的环境，让辐射工作人员工作。超热中子和快中子的均匀分布在LHD附近。特别是，由于快中子的快速能量损失，观察到快中子通量随离LHD的距离增加而显著减少。的中子通量分布测量，与粗略的能量歧视的基础上的阈值能量的中子活化箔，使我们能够估计的空间辐射剂量率，以及组件中的放射性在环面大厅。对混凝土地面放射性的预测表明，在为期9年的氘实验活动结束后，放射性同位素~（55）Fe将成为混凝土地面放射性的主要来源。
The global flux distributions for thermal, epithermal and fast neutrons in the torus hall of large fusion devices were experimentally evaluated for the first time in the Large Helical Device (LHD) using the activation foil method measured by the imaging plate and high-purity germanium detector. It turned out that the thermal neutrons were effectively absorbed by borated polyethylene blocks placed beneath the LHD. This should reduce the radioactivity of the floor and would be beneficial in maintaining a good environment for radiation workers. Uniform distributions of epithermal and fast neutrons were observed near the LHD. In particular, the significant decrease in fast neutron flux with increasing distance from the LHD, due to the fast energy loss of fast neutrons, was observed. The neutron flux distribution measurement, with rough energy discrimination based on the threshold energy of the neutron activation foil, allows us to estimate the spatial radiation dose rate, as well as the radioactivity in components in the torus hall. The prediction of the radioactivity in the concrete floor indicated that radioactive isotope 55Fe will be a dominant source of radioactivity in the concrete after the nine-year deuterium experiment campaign finishes.
(p)ppGpp 合成以及代谢酶 SpoT 控制环脂肽的产生
DOI：
--
发表时间：
2010
期刊：
影响因子：
--
作者：
鷲尾健司;Siew Ping Lim;Niran Roongsawang;森川正章
通讯作者：
森川正章