Improving the Understanding of Gadolinium for use in Neutron Detectors

提高对用于中子探测器的钆的了解

• 批准号: 2615176
• 金额: --
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2615176
• 关键词: Improving; Understanding; Gadolinium; use; Neutron

Gadolinium has a very high neutron capture cross section, particularly isotopes Gd-155 and Gd-157 and produces a very high energy upon emission of a gamma cascade (~8MeV). However, this model for decay is not well understood, so we hope to improve this model via both computational and experimental methods. We hope to achieve a good model for the gadolinium mechanism of thermal neutron capture; this improved understanding will lead to better neutron detection via event identification and background discrimination. Neutron detectors that employ Gadolinium (Gd) as the neutron capture agent can be enhanced by improving the understanding of the subsequent gamma cascade of the neutron capture on Gd. This would open up a new area of development where the neutron has the potential to be (partially) tagged, resulting in better background discrimination. This is particularly useful in large area detectors where intrinsic radiation in the scintillator or the photo-sensor itself is a large source of background, enabling new deployment scenarios. Gd has an extremely large thermal neutron capture cross-section, second only to the capture cross-section of Xenon. The neutron capture on Gd has a Q-value of 8-MeV resulting in an associated gamma-ray cascade.Gd(n, gamma) interactions have been studied and the integrated spectrum is known, but the individual decay modes have not been measured. The 4-gamma mode is dominant, although these are not measured to be discrete energies and it is not known if the energy of the four gammas is equal to the Q-value of the decay (8 MeV). Given the available energy there is likely to be multiple sub-MeV cascades. The PhD will calculate and measure the gamma spectrum, hence determining what is missing in each detected event and allowing the events to be tagged.

Gd具有非常高的中子俘获截面，特别是同位素Gd-155和Gd-157，并在伽马级联发射时产生非常高的能量(~8 MeV)。然而，这个衰变模型并没有被很好地理解，所以我们希望通过计算和实验方法来改进这个模型。我们希望为热中子俘获的Gd机制建立一个很好的模型；这种理解的改进将导致通过事件识别和背景识别更好地进行中子探测。使用Gd(Gd)作为中子捕获剂的中子探测器可以通过提高对Gd上中子俘获的后续伽马级联的理解来增强。这将开辟一个新的发展领域，在那里中子有可能被(部分)标记，从而产生更好的背景歧视。这在大面积探测器中特别有用，在这种探测器中，闪烁体或光传感器本身中的本征辐射是一个大的背景源，从而实现了新的部署方案。Gd具有极大的热中子俘获截面，仅次于氙气的俘获截面。Gd上的中子俘获具有8 MeV的Q值，导致伴随的伽马射线级联。已经研究了Gd(n，伽马)相互作用，并已知积分谱，但尚未测量到单独的衰变模式。4伽马模式占主导地位，尽管这些能量没有被测量为离散能量，而且还不知道四个伽马的能量是否等于衰变的Q值(8 MeV)。考虑到可用能量，很可能会有多个亚MeV级联。PHD将计算和测量伽马光谱，从而确定每个检测到的事件中缺失了什么，并允许对事件进行标记。