Development of advanced monoenegetic neutron source using a tandem accelerator and its neutron beam applications

我们在九州大学串联加速器实验室（KUTL）研制了一种MeV区域的新型单能中子源。根据（p,n）反应的逆运动学，选择^1H（^<13>C,n）反应作为产生单能中子的核反应，期望在有限角度内在前锥内发射一个中子。用59.3MeV ^<13>C^<6+>束流入射氢气靶上进行了可行性试验。通过中子源模拟计算，可以在30度内的前锥内产生7.2MeV的0度运动准直单能中子。此外，对用于TOF实验的光束脉冲系统进行了优化，使4.0 mevdeuteron光束的时宽达到3.8ns。研制了基于反冲质子法的高性能中子能谱仪，并进行了性能测试。设计并制作了主动辐射式质子反冲反望远镜和射线示踪式质子反冲反望远镜。研究了用于MeV中子监测仪的6Li捕获门快中子光谱仪的性能。结果表明，这些中子能谱仪适用于今后利用所研制的中子源进行的实验。此外，还建立了C、Mg和Si高达3GeV的中子截面数据库，并研究了半导体器件中中子引起的软误差与未来中子束应用的关系。

We have developed a new type of monoenergetic neutron source in the MeV region at Kyushu University Tandem Accelerator Laboratory(KUTL). The ^1H(^<13>C,n) reaction was chosen as a nuclear reaction to generate a monoenergetic neutron, which is based on the inverse(p,n) reaction kinematics and a neutron is expected to be emitted in the forward cone within a limited angle. A feasibility test experiment was performed using a 59.3MeV ^<13>C^<6+> beam incident on a hydrogen gas target. It was shown that kinematically collimated monoenergetic neutrons with 7.2MeV at 0 degree can be produced in the forward cone within 30 degree as expected by a neutron source simulation calculation. In addition, an optimization of a beam pulsing system was made for TOF experiments, and the time width of 3.8ns was achieved for a 4.0-MeVdeuteron beam. Also, high performance neutron spectrometers based on a recoil proton method were developed and their performance tests were made. An active radiator proton recoil counter telescope and a ray-trace-type proton recoil counter telescope were designed and fabricated. The performance of a fast neutron spectrometer with ^6Li capture gate was investigated for a MeV neutron monitor. As a result, it was demonstrated that these, neutron spectrometers are applicable to future experiments using the developed neutron source. Furthermore, a database of neutron cross sections for C,Mg,and Si up to 3GeV was developed and the neutron-induced soft error in semiconductor devices was studied in relation with future neutron beam applications.