ARI-MA: Fabrication of Solid-State Large Area Thermal Neutron Detectors at a Low Cost

1348269 (Danon)。对铀和铀等核材料的探测通常是利用它们的自然或诱导中子发射来完成的。这种系统通常在塑料慢化剂内使用热中子探测器。为了获得较高的探测效率，采用He-3或BF-3填充热中子探测器；这些检测器需要高电压偏置才能工作，当许多检测器在一个系统中使用时，这会使系统复杂化。此外，氦-3探测器体积庞大，不适合便携式应用。一种更好的探测器将是一种廉价的固态探测器，它可以像任何其他计算机芯片一样大规模生产。如果这样的探测器不需要操作偏置，可以生产小或大的表面积，具有低灵敏度和快速响应，它将是未来中子探测系统理想的低成本探测器。这种探测器是在伦斯勒理工学院开发的，演示面积为8平方厘米（单个商用前置放大器），测量效率为30%，中子为0.0253 eV。这个项目的重点是改进制造工艺，利用硅（110）的湿法蚀刻，硼纳米颗粒的电泳沉积，以及紧凑的集成电子读数的设计。这些改进将显著降低生产成本，同时由于更深的硅蚀刻而提高性能。最终的目标是成为一种低成本的固态热中子探测器，适用于许多与DNDO相关的应用。知识价值包括开发新的低成本硼纳米颗粒沉积方法来取代LPCVD工艺。还包括大纵横比湿法刻蚀法；这是目前使用的博世工艺的低成本替代品。为了进一步显著提高整体效率，在与紧凑的集成电子读出器接口之前，将多个器件晶片堆叠在一起。另外的贡献是教育学生在核探测器的发展领域，包括辐射与物质的相互作用和固体探测器的制造。这一提议的更广泛的影响是开发一种新型的高效率自供电固体中子探测器，生产成本低。器件制造的发展将导致一种基于太阳能电池技术的新型带电粒子探测器。除了国土安全应用外，这些技术还应用于核工业和研究中使用的中子剂量测定和监测。

1348269 (Danon). Detection of nuclear materials such as U and Pu is often accomplished by utilizing their natural or induced neutron emission. Such systems typically use thermal neutron detectors inside a plastic moderator. In order to achieve high detection efficiency He-3 or BF-3 filled thermal neutron detectors are utilized; these detectors require high voltage bias for operation, which complicates the system when many detectors are used in one system. In addition He-3 detectors are bulky and do not fit well for portable applications. A better type of detector would be an inexpensive solid-state detector that can be massively produced like any other computer chips. If such a detector does not require a bias for operation, could be produced with small or large surface area, and has a low gamma sensitivity and fast response, it will be the ideal low-cost detector for future neutron detection systems. Such detector was developed at Rensselaer Polytechnic Institute with demonstrated area of 8 cm2 (with single commercial preamplifier) and measured efficiency of 30% for 0.0253 eV neutrons. This project focuses on improvements of the fabrication process to utilize wet etching of Si (110), electrophoretic deposition of boron nanoparticles, and a design of compact integrated electronic readout. These improvements will reduce the production cost significantly, while improving the performance due to deeper silicon etching. The end result is targeted to be a low cost solid-state thermal neutron detector that is suitable and ready for use in many DNDO related applications. Intellectual merit includes development of new low-cost boron nanoparticle deposition methods to replace the LPCVD process. It also includes wet etching method with large aspect ratio; a low cost alternative to currently used Bosch process. In order to significantly improve the overall efficiency further, multiple device wafers are stacked together before interfacing with the compact integrated electronic readout. Additional contribution is education of students in the area of nuclear detector development that includes radiation interaction with matter and solid- state detector fabrication. The broader impact of this proposal is the development of a novel type of high efficiency self-powered solid-state neutron detector with a low production cost. The development in device fabrication will result in a new type of charged particle detectors based on solar-cell technology. In addition to homeland security applications, these technologies have applications in neutron dosimetry and monitoring used in the nuclear industry and research.