Development of High Energy Resolution Neutron Spectrometer for Fusion Reactor Material Irradiation Test Faclility

本研究的目的是开发一种新型的中子探测器，适用于常规监测加速器中子源，预计聚变堆材料辐照试验实验。探测原理是基于斜散射几何的反冲核计数器望远镜技术，其独特的设计思想是在入射中子束的方向上平行放置一个大面积的反冲核发射器（辐射器），并在辐射器和反冲核探测器之间远离中子束的位置插入一个多微准直板。该系统的优点是通过调整探测器元件的几何参数，如辐射体厚度、面积、反冲核微准直器的形状等，可以实现高能量分辨率、高探测效率与良好的抗辐射性能的兼容。1.针对聚变堆材料辐照试验所需的1 ~ 50 MeV能区中子，编制了精确计算探测器响应的程序。3.根据14 MeV中子源监测的要求，通过优化设计实例，建立了确定探测器性能指标的方法。4.探讨了反冲核微准直板制造的可能性，5.通过对14 MeV以上能区中子能谱测量的设计考虑，阐明了预期的性能和存在的问题。

The present study is aiming at the development of a new type neutron detector suitable for routine monitoring of accelerator neutron sources which are expected for fusion reactor material irradiation test experiments. The detection principle is based on recoil nucleus counter telescope technique in oblique scattering geometry with unique ideas that a large area recoil nucleus emitter (radiator) is placed In parallel to the incident neutron beam and a multi-micro collimation plate for recoil nuclei is inserted between the radiator and recoil nucleus detectors away from the neutron beam. The excellence of this system can reaIize the compatibility of high enegy resolution and high detection efficiency together with good radiation resistance by adjusting the geometrical parameters of the detector elements such as the radiator thickness and area, the shape of recoil nucleus microcollimators, etc.The main research results are summarized as follows ;1.The program to calculate the precise detector response was developed for neutrons in the energy region between 1 and 50 MeV expected for fusion reactor material irradiation test experiments.2.A prototype detector correspnding to 1/24 model was manufactured and the performance test was made by using an accelerator 14MeV neutron source, of which results verified the validity of the present detector concept and design calculation3.The procedure to determine the detector specification was established through an example design optimized to the requirements for 14MeV neutron source monitoring4.The posibility of manufacturing a recoil nucleus microcollimation plate, which is essential to reaIize the present detector concept, was demonstrated by some micromacnining technique.5.The predicted performance and problems were made clear through design consideration for neutron spectrometry in the energy region higher than 14MeV.