Collaborative Research: ARI-MA Development of Improved CMT and CZT Nuclear Detectors for Homeland Security Applications

合作研究：ARI-MA 开发用于国土安全应用的改进型 CMT 和 CZT 核探测器

• 批准号: 1140001
• 负责人: Jeffrey Derby
• 金额: $ 12万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1140001&HistoricalAwards=false
• 关键词: Collaborative; Research; ARI; MA; Development

The goal of this project is to develop high-resolution Cadmium Manganese Telluride (CMT) and Cadmium Zinc Telluride (CZT) materials for nuclear and radiological detection applications in homeland security. These materials have emerged as promising advanced detectors for X-ray and gamma-ray spectroscopy and imaging without cryogenic cooling. Advances in research have led to the development of CZT for commercial devices, but there is still the presence of defects such as Tellurium (Te) inclusions that limit the performance of large-volume CZT and CMT detectors that are needed for nuclear and radiological detection applications. The results of this project will provide benefit to society, with high impact on the science and technology of semiconductor nuclear detectors for room-temperature applications in homeland security (maritime and port security, border security, transportation security, nonproliferation and domestic nuclear security). The outcomes also include new capabilities that are very important to the success of emerging detector technologies and analysis tools needed to support next-generation nuclear materials management and safeguards. This project advances discovery and understanding while promoting teaching, training, and learning.The project team will use theory-based design, knowledge-based processing and fabrication, and novel experimental techniques to develop improved cadmium manganese telluride (CMT) and cadmium zinc telluride (CZT) materials for high-resolution nuclear detection applications. The project will enhance the science and expand the overall knowledge in this area by using a combination of theory, modeling and experiments to complete the following tasks: 1) optimization of the Bridgman methods and Traveling Heater Method (THM) for growth of improved CMT and CZT crystals; 2) a novel post-growth annealing and doping process for removing performance-limiting defects caused by tellurium inclusions and associated impurities in CMT and CZT detector materials; and 3) improved surface passivation and detector fabrication techniques to produce better detectors. These methods employ state-of-the-art instrumentations that incorporate 3D-infrared transmission spectroscopy and advanced measurement tools to probe and collect data during the post-growth annealing process. The development of in-situ tools to monitor crystal annealing adds a new experimental dimension that will lead to any improved understanding of the migration of tellurium inclusions and novel methods to minimize their impact on electron trapping. The end result will be CMT and CZT detectors with better resolution, improved detection efficiency and better directional sensitivity. The outcomes from the modeling aspects of this project will provide an understanding of fundamental phenomena associated with Bridgman and THM growth of ternary II-VI compounds and suggestions regarding post-growth treatments to improve the microstructural properties of these crystals. The anticipated impact of in-situ probing and data collection techniques will include new insights into the science and dynamical properties of post-growth annealing, uniform doping of detector materials, migration of Te secondary phases and impurities, and methods to process detector surfaces. This project advances discovery and understanding while promoting teaching, training, and learning. It is multidisciplinary with investigators from the following collaborating entities: Alabama A&M University, University of Minnesota ? Twin Cities, Brookhaven National Laboratory (BNL), FLIR Radiation Inc, and the Interdisciplinary Consortium for Research and Educational Access in Science and Engineering (INCREASE). The workforce development component of this project will provide opportunities for women and under-represented minorities to build careers and earn graduate degrees in areas critical to the development of cutting-edge nuclear and radiological detection technology.

该项目的目标是开发高分辨率碲锰镉（CMT）和碲锌镉（CZT）材料，用于国土安全中的核和放射性探测应用。 这些材料已经成为有前途的先进探测器，用于X射线和伽马射线光谱学和成像，而无需低温冷却。 研究的进展已经导致CZT用于商业设备的开发，但是仍然存在缺陷，例如碲（Te）夹杂物，其限制了核和放射性检测应用所需的大体积CZT和CMT检测器的性能。 该项目的成果将造福社会，对用于国土安全（海事和港口安全、边境安全、运输安全、不扩散和国内核安全）的室温半导体核探测器的科学和技术产生重大影响。这些成果还包括新的能力，这些能力对于支持下一代核材料管理和保障监督所需的新兴探测器技术和分析工具的成功非常重要。 该项目将利用基于理论的设计、基于知识的加工和制造以及新颖的实验技术，开发用于高分辨率核探测应用的改进型碲化镉锰（CMT）和碲化镉锌（CZT）材料。 本项目将通过理论、模拟和实验相结合的方法，完成以下任务：1）优化Bridgman法和移动加热器法（THM）生长改进的CMT和CZT晶体; 2）用于去除性能的新的生长后退火和掺杂工艺-限制由CMT和CZT探测器材料中的碲夹杂物和相关杂质引起的缺陷;以及3）改进的表面钝化和探测器制造技术，以生产更好的探测器。这些方法采用最先进的仪器，结合3D红外透射光谱和先进的测量工具，以探测和收集生长后退火过程中的数据。 原位工具的发展，以监测晶体退火增加了一个新的实验层面，这将导致任何改进的理解碲夹杂物的迁移和新的方法，以尽量减少其对电子捕获的影响。 最终的结果将是CMT和CZT探测器具有更好的分辨率、更高的探测效率和更好的方向灵敏度。从这个项目的建模方面的结果将提供与布里奇曼和THM生长的三元II-VI化合物和建议有关的生长后处理，以改善这些晶体的微观结构特性的基本现象的理解。 原位探测和数据收集技术的预期影响将包括对生长后退火的科学和动力学特性的新见解，探测器材料的均匀掺杂，Te第二相和杂质的迁移，以及处理探测器表面的方法。 该项目推进发现和理解，同时促进教学，培训和学习。 它是多学科的研究人员从以下合作实体：亚拉巴马A M大学，明尼苏达大学？双城，布鲁克海文国家实验室（BNL），FLIR辐射公司，和跨学科联盟的研究和教育机会在科学和工程（增加）。该项目的劳动力发展部分将为妇女和代表性不足的少数民族提供机会，在发展尖端核和放射性探测技术的关键领域建立职业生涯并获得研究生学位。