新型高位置分辨和高gamma射线甄别能力的热中子探测器研究

项目提出了一种新型基于含锂6或硼10微通道结构的高位置分辨（微米量级）且具有高gamma射线甄别能力的热中子探测器。与现有的微通道板热中子探测器的主要不同点是:探测器探测热中子反应产物径迹而不是统计平均，这意味着微米量级的高位置分辨（利用径迹重建技术）和高gamma甄别能力（利用径迹的差异）。具体的研究内容如下：1）编写蒙特卡洛模拟程序，模拟热中子的转换，电子传输和放大，微通道结构参数等对探测器性能的影响，指导探测器设计和实验工作；2）研究并制作基于硅和玻璃的微米孔径的微通道结构；3）研究锂6和硼10在微结构中的最佳扩散工艺；4）采用原子层沉积技术，在孔径内壁沉积含锂6或硼10的电子发射层；5）设计并制作探测器，优化电子传输，光传输和光耦合；6）基于Hugh算法和射程理论编写径迹重建程序和中子反应点识别程序。通过具体的模拟和实验，制作出位置分辨为2微米且具有接近氦3管甄别能力的热中子探测器

A new thermal neutron detector with a high spatial resolution (in microns) and a high neutron-gamma discrimination ability based on the Li-6 or B-10 doped microcapillary array is proposed. Compared with the current widely investigated thermal neutron detector based on the boron and gadolinum co-doped microchannel plate, the proposed one has its advantage: through detecting the tracks of the neutron reaction products instead of the statistical average of tracks, a higher spatial resolution and high neutron-gamma discrimination ability are expected. The detailed studies include that 1) Writing a Monte Carlo simulation program, and then simulating the thermal neutron conversion process, the electron production, transportation and amplification, the optimized parameters of the microstructures, etc.; 2) studing and manufacturing the microcapillary structure based on silicon and glass materials; 3) investigating and optimizing the method to produce the microstructure with high Li-6 and/or B-10 concentrations; 4) using the ALD technique to deposit electron emission materials enriched with Li-6 and B-10 on the inner wall of capillary arraies; 5) designing and manufacturing the micro-structure thermal neutron detector, optimizing its electron transportation efficiency, photon transportation efficiency, and optical coupling; 6) Developing the track reconstruction program and the reaction point of neutron and detector material base don Hugh algorithm and ion transportation theory in matter. With quasi-thermal neutrons from a 252Cf neutron source and a nuclear reactor, the performance of the detector will be characterized and optimized and finally obtain a thermal neutron detector with a spatial resolution of 2 microns and the gamma discrimination ability close to that of helium-3 tube detector.