4pi gamma-ray detection system

该提案将为整个系统的三个主要阶段之一的关键升级提供资金，以非侵入性地测量人体中的有毒元素。整个项目是人体骨骼中锰（Mn）和铝（Al）元素的体内中子活化分析（IVNAA）。IVNAA涉及小剂量的受控中子辐射（有点类似于X射线或核医学扫描）。使靶元素（在这种情况下为Mn或Al）的一些原子具有放射性，并且可以测量该放射性，从而测量存在的Mn或Al的量。第一阶段是产生中子，这是在实验室中已经存在的加速器中完成的。第二阶段是辐射腔，这也是已经可用的。第三个阶段是探测器阵列测量活动。有一个现有的阵列，组装从另一个实验室，是退役的另一个仪器。重新启用的阵列中的一些个别探测器的性能不再良好。这笔资金主要用于更换两台运行不佳的探测器。这将提高整个阵列的性能。重要的是要衡量这些因素。锰是必需的，但过量是有毒的。在工作场所暴露于锰、由此产生的骨骼中的储存水平和随后可能的健康影响之间的关系还完全不清楚。同样，铝是有毒的，对正常的骨功能有有害影响。关于Al是否可以在阿尔茨海默病的病因中发挥作用也存在持续的争议。能够测量骨骼中这些元素的储存水平将有助于更好地了解健康影响，从而防止伤害。

This proposal will fund key upgrades to one of three principal stages of an overall system to measure toxic elements non invasively in human subjects. The overall project is in vivo neutron activation analysis (IVNAA) of the elements manganese (Mn) and aluminum (Al) in bone of human subjects. IVNAA involves a small controlled dose of neutron radiation (somewhat analogous to an x-ray or to a nuclear medicine scan). A few of the atoms of the target element (Mn or Al in this case) are made radioactive and this activity can be measured, resulting in a measurement of the amount of the Mn or Al present. The first stage is to produce neutrons, this is done in an accelerator, which is already present in the laboratory. The second stage is an irradiation cavity, this is also already available. The third stage is the detector array to measure the activity. There is an existing array, assembled from parts acquired from another laboratory that was decommissioning another instrument. Some of the individual detectors in that re-commissioned array are no longer performing well. This funding is primarily to replace the two detectors that are not functioning well. This will enhance the performance of the whole array. It is important to measure these elements. Mn is essential, but in excess it is toxic. The relationship between exposure to Mn in the workplace, resultant stored levels in bone and then possible health effects is not at all well known. Similarly, Al is toxic, with harmful effects on normal bone function. There is also continuing controversy as to whether Al can play a part in the causation of Alzheimer's Disease. Being able to measure stored levels of these elements in bone will contribute towards a better understanding of the health impact and then to preventing harm.