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

我们在九州大学串列加速器实验室(KUTL)研制了一种新型的MeV区单能中子源。选择^1H(^&lt；13&gt；C，n)反应作为产生单能中子的核反应，该反应基于逆(p，n)反应运动学，并期望在有限角度内在前锥体中发射一个中子。用一束59.3 MeV~(-13)的束流入射到氢气靶上进行了可行性实验。中子源模拟计算表明，在前锥体内30度内就能产生7.2 MeV零度运动准直的单能中子。此外，还对TOF实验中的束流脉冲系统进行了优化，得到了4.0 MeV重离子束流的时间宽度为3.8 ns。研制了基于反冲质子方法的高性能中子谱仪，并进行了性能测试。设计并制作了有源辐射体质子反冲计数器望远镜和光线追踪型质子反冲计数器望远镜。研究了MeV中子监测器用6Li俘获门快中子能谱仪的性能。结果表明，这些中子谱仪适用于未来利用所研制的中子源进行的实验。此外，还建立了3GeV以下的C、Mg和Si的中子截面数据库，并结合未来的中子束应用研究了半导体器件中中子引起的软误差。

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.