Miniature Dysprosium-Based Monitors of Thermal Neutron Exposure History

基础研究提出了一种新的概念，用于结合中子探测和检索有关热中子暴露的水平和时间的信息，这些信息可能发生在恢复由微型纳米晶体传感器存储的数据之前。这个概念是基于镝的一种主要的天然同位素Dy的独特性质，Dy在暴露于热中子中时转化为165m的亚稳态，然后衰变为钬的稳定同位素，或者在捕获第二个中子时，变成稳定的铒同位素。结合~ 2650 barns的高热中子捕获截面和嬗变成另外两种镧系元素，使镝成为一个很好的候选者。将合成各种化学成分的含镝纳米晶体，掺杂Ho和Er，并进行光学表征，以最大限度地区分三种镧系元素。中子暴露数据的重建将通过纳米晶体样品的光谱分析来证明。基础研究提出了一种新的概念，用于结合中子探测和检索有关热中子暴露的水平和时间的信息，这些信息可能发生在恢复由微型纳米晶体传感器存储的数据之前。这个概念是基于天然存在的镝同位素164Dy的独特性质，它在暴露于热中子时转化为亚稳态165mDy，然后衰变成稳定的钬同位素165Ho，或者在捕获第二个中子时，变成稳定的铒同位素166Er。结合~ 2650 barns的高热中子捕获截面和嬗变成其他两种镧系元素，使得164Dy对所提出的新传感器非常有吸引力。将合成各种化学成分的含镝纳米晶体，掺杂Ho和Er，并进行光学表征，以最大限度地区分三种镧系元素。中子暴露数据的重建将通过纳米晶体样品的光谱分析来证明。教育部分将强调传统学科之间的合作和互动，提议的项目跨越化学、物理、电气工程和核工程领域。

Fundamental research is proposed on a novel concept for combined neutron detection and retrieval of information about the level and timing of thermal neutron exposure that may have occurred prior to recovery of the data stored by a miniature, nanocrystal-based sensor. The concept is based on the unique properties of a dominant naturally occurring isotope of dysprosium,Dy, which upon exposure to thermal neutrons converts into a metastable state 165m, and then subsequently decays into a stable isotope of holmium, or, upon capturing a second neutron, into a stable erbium isotope. Combination of the high thermal neutron capture cross section of ~2,650 barns and transmutation into two other lanthanides makes dysporium a good candiate. Dy-containing nanocrystals of various chemical compositions will be synthesized, doped with Ho and Er, and optically characterized for maximum spectral differentiation between the three lanthanides. Reconstruction of data about neutron exposure will then be demonstrated by optical spectral analysis of the nanocrystalline samples. Fundamental research is proposed on a novel concept for combined neutron detection and retrieval of information about the level and timing of thermal neutron exposure that may have occurred prior to recovery of the data stored by a miniature, nanocrystal-based sensor. The concept is based on the unique properties of a dominant naturally occurring isotope of dysprosium, 164Dy, which upon exposure to thermal neutrons converts into a metastable state 165mDy, and then subsequently decays into a stable isotope of holmium 165Ho, or, upon capturing a second neutron, into a stable erbium isotope 166Er. Combination of the high thermal neutron capture cross section of ~2,650 barns and transmutation into two other lanthanides makes 164Dy very attractive for the proposed new sensor. Dy-containing nanocrystals of various chemical compositions will be synthesized, doped with Ho and Er, and optically characterized for maximum spectral differentiation between the three lanthanides. Reconstruction of data about neutron exposure will then be demonstrated by optical spectral analysis of the nanocrystalline samples. The educational component will emphasize collaboration and interactions across traditional academic disciplines, with the proposed project spanning the fields of chemistry, physics, electrical engineering, and nuclear engineering.