SGER: IMR: Development of Efficient Thermal Neutron Position Sensitive Detectors

一个小组计划开发一种基于硼和钆掺杂微通道板（MCPs）的新型热中子和冷中子计数探测器。新型中子成像探测器将对热中子成像进行优化，具有高探测效率（高达50%），对冷中子的探测效率更高，每个探测中子的空间分辨率（~55µm）和时间分辨率为~1 ms（或门控探测，门控精度为1µs）。具有Medipix读出的检测器计数率可高达100 MHz，有效面积可扩展到28 x (N*14) mm2的矩形配置。探测器的另一个吸引人的特点是它能够与外部触发器同步，允许脉冲源的能量选择成像。中子成像设备将在中子束线上进行严格的测试，我们将与新星科学公司的同事合作。所提出的探测系统将极大地促进热中子成像，具有非常高的计数率、灵敏度和分辨率，大大提高现有实验的准确性（例如，使用工程仪器Vulcan测量SNS残余应力剖面，使用高压仪器SNAP研究非常高压下的小样本，燃料电池研究）。并可能进一步开辟现代中子源无损检测的全新领域。摘要中子是不带电荷的核粒子，对研究原子结构细节非常有用。它们特别有用，因为它们可以探测原子排列，研究重要的材料性质，如磁性和晶体中原子的振动性质。然而，探测中子一直是一个挑战。这项提议计划使用带有许多细孔的玻璃片作为中子探测器。中子穿过空穴，与空穴边缘的玻璃相互作用，然后，由于玻璃的特殊性质（添加了硼或钆），中子被转换成光，然后可以被探测到。小孔的小尺寸使得每个中子的定位精度非常高，因此可以构建图像。此外，这个探测器系统可以以与最好的中子源产生的中子相同的速率来计数中子，从而允许充分利用这些新中子源的实验。

Technical AbstractOur group plans to develop a novel type of thermal and cold neutron counting detector based on Boron and Gadolinium doped microchannel plates (MCPs). The new type of neutron imaging detectors will be optimized for imaging thermal neutrons with high detection efficiency (up to 50 %) and even higher for cold neutrons, spatial (~55 µm) and time resolution of ~1 ms (or gated detection with gate accuracy 1 µs) for each detected neutron. The counting rate of detector with Medipix readout can be as high as 100 MHz with active area scalable to rectangular configuration of 28 x (N*14) mm2. Another attractive feature of the detector will be its ability to be synchronized with the external trigger, allowing energy selective imaging with a pulsed source. The neutron imaging devices will be rigorously tested at a neutron beamline, in collaboration with our colleagues from Nova Scientific. The proposed detection system will greatly facilitate thermal neutron imaging with very high counting rates, sensitivity and resolution, substantially increasing the accuracy of existing experiments (e.g. SNS residual stress profile measurements with the engineering instrument Vulcan, studies of small samples under very high pressures with the high pressure instrument SNAP, fuel cell studies), and may additionally open up entirely new areas of non destructive testing with modern neutron sources. Non-technical AbstractNeutrons are nuclear particles with no electronic charge which are very useful for studying the details of structure at the atomic level. They are particularly useful because they can probe atomic arrangements and study important materials properties such as magnetism and the vibrational properties of atoms in a crystal. However, detecting neutrons has always been a challenge. This proposal plans to use pieces of glass with many fine holes as a neutron detector. The neutrons pass through the holes, interact with the glass at the edge of the holes, and then, because of the special properties of the glass (addition of Boron or Gadolinium) the neutrons are converted to light, which can then be detected. The small size of the holes allows very high precision in locating the position of each neutron, so that images can be constructed. In addition, this detector system can count neutrons at the same rate that they are produced in the best neutron sources, allowing experiments that take full advantage of those new sources.