镝活化法测量低产额脉冲中子

Measurement of Low-Yield Pulse Neutron by Dy Activation

摘要: 设计一个快中子聚乙烯慢化体，用来慢化加速器的d-T和d-D中子，利用¹⁶⁴Dy(n,γ)¹⁶⁵Dy^m在热中子区极高的反应截面，得到半衰期为75 s的¹⁶⁵Dy^m，使用HPGe探测器测量¹⁶⁵Dy^m放出的γ射线。由于测得的γ射线与加速器的中子产额成一定比例，故通过这种方法可测量脉冲中子源的中子产额。

Abstract: A polyethylene moderator was designed for moderating d-T and d-D neutrons from neutron generator. The cross-section of ¹⁶⁴Dy(n,γ)¹⁶⁵Dy^m is very large for the thermal neutron, so that lots of ¹⁶⁵Dy^m are produced in the moderator. The half life of ¹⁶⁵Dy^m is 75 s, and it emits ample gamma rays. The gamma rays were measured by HPGe detector. The amount of γ-ray is proportional to the neutron yield, hence the yield of pulse neutron source can be measured.