Semi-monoenergetic neutron field for activation experiments up to 40 MeV
Semi-monoenergetic neutron field for activation experiments up to 40 MeV
复制标题
用于高达 40 MeV 激活实验的半单能中子场
DOI：
10.1016/0168-9002(88)90318-x
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发表时间：
1988
影响因子：
1.4
通讯作者：
Takashi Nakamura
中科院分区：
文献类型：
--
作者：
Y. Uwamino;T. Ohkubo;Atsushi Torii;Takashi Nakamura
在东京大学核研究所的SF回旋加速器上，利用20、25、30、35和40 MeV质子轰击的简单Be靶系统，开发了用于活化实验的半单能高能中子场。1和2 mm厚的Be靶分别由12和11 mm厚的层的水流冷却，其同时用作质子束阻挡器。用NE-213闪烁计数器测量了中子能谱，并通过计算校正了高能峰的能量分辨率。能量超过3 MeV的总中子的强度为4× 1015 ~ 1.6×1016[n sr−1C−1]，高能峰值中子的强度为2× 1015 ~ 7×1015[n sr−1C−1]。激活实验的辐照点在离靶20 cm处，束流约为5 μA。测量了27 Al（n，α）、197 Au（n，2n）和197 Au（n，4 n）在辐照点的反应率，并与文献中用修正的中子能谱和截面计算的结果进行了比较。对于前两个反应，计算值与实测值吻合较好，但文献中的197 Au（n，4 n）反应截面数据被高估。
A semi-monoenergetic high-energy neutron field for activation experiments was developed at the SF cyclotron of the Institute for Nuclear Study, the University of Tokyo, using a simple Be target system bombarded by 20, 25, 30, 35 and 40 MeV protons. The 1 and 2 mm thick Be targets were cooled by a water flow of 12 and 11 mm thick layers, respectively, which works as a proton beam stopper at the same time. The neutron spectra were measured with an NE213 scintillation counter and the energy resolution at their high energy peaks was corrected by calculations. The intensity was 4×1015to 1.6×1016[n sr−1C−1] for the total neutrons of energy above 3 MeV, and 2×1015to 7×1015[n sr−1C−1] for the high-energy peak neutrons. The irradiation point for the activation experiment is at 20 cm from the target, and the beam current is about 5 μA. The27Al(n, α),197Au(n, 2n) and197Au(n, 4n) reaction rates at the irradiation point were measured and they were compared with the calculation performed with the corrected neutron spectra and the cross sections in references. For the former two reactions, the measured and calculated data agreed well with each other, and the197Au(n, 4n) reaction cross section data in the reference were found to be overestimated.