Uncooled Semiconductor Nuclear Radiation Detectors

该奖项的研究目的是验证与半导体通道上的核辐射相关的电磁场将通过Rashba自旋轨道相互作用机制与电子的自旋相互作用的假设。该方法将是设计由宽带隙半导体通道组成的四端非局部自旋阀器件，其中四个电极将沉积在其上。内两个电极将由铁磁性金属制成，而外两个电极将由非磁性金属制成。为了使磁电极的矫顽力不同，有意保持磁电极的几何形状不同，从而可以独立地改变磁电极的相对取向（平行或反平行）。这些自旋阀传感器将暴露在受控的辐射环境中，并将进行磁电阻和汉勒效应的非局部测量。实验研究将通过蒙特卡罗模拟和理论建模来理解半导体中辐射-自旋相互作用的机制。如果成功，这项研究将导致室温核辐射探测器，将在各种民用，机械，制造，医学成像和安全系统中找到应用。研究成果将大大减少核威胁和辐射威胁，造福整个社会。该项目将通过让K-12、本科生和研究生参与跨学科的合作研究活动来促进学习和教育。该项目的研究成果将由主要研究人员和研究生在相关的技术会议上发表。研究成果将发表在高影响力的同行评议期刊上。

The research objective of this award is to test the hypothesis that the electromagnetic field associated with the nuclear radiation incident on semiconductor channels will interact with the spin of the electrons via the Rashba spin-orbit interaction mechanism. The approach will be to design 4-terminal non-local spin-valve devices comprised of wide band-gap semiconductor channels over which four electrodes will be deposited. Inner two electrodes will be made out of a ferromagnetic metal while the outer two electrodes will be made out of a nonmagnetic metal. Geometry of the magnetic electrodes will be kept different deliberately in order to make their coercivities dissimilar so that their relative orientation (parallel or antiparallel) could be changed independently. These spin-valve sensors will be exposed to controlled radiation environments and non-local measurements of magneto-resistance and Hanle-effect will be performed. Experimental research will be supported by Monte Carlo simulation and theoretical modeling to understand the mechanism of radiation-spin interaction in semiconductors. If successful, this research will lead to room-temperature nuclear radiation detectors which will find applications in various civil, mechanical, manufacturing, medical imaging and security systems. The research outcomes will greatly reduce nuclear and radiological threats and benefit the society at large. The project will promote learning and education by involving K-12, undergraduate and graduate students in the inherently interdisciplinary cooperative research activities. The discoveries of this project will be presented at related technical conferences by the principal investigators and graduate students. Research results will be published in high impact peer-reviewed journals.