4pi gamma-ray detection system

这项提案将资助对整个系统的三个主要阶段之一的关键升级，以非侵入性地测量人体受试者中的有毒元素。整个项目是人体骨骼中元素锰(Mn)和铝(Al)的活体中子活化分析(IVNAA)。IVNAA包括少量受控剂量的中子辐射(有点类似于X光或核医学扫描)。靶元素的几个原子(在这种情况下是锰或铝)具有放射性，这种活度可以被测量，从而得到对存在的锰或铝的量的测量。第一个阶段是产生中子，这是在实验室已经存在的加速器中完成的。第二阶段是照射腔，这也是已经可用的。第三阶段是用于测量活度的探测器阵列。有一个现有的阵列，由从另一个实验室获得的部件组装而成，该实验室正在退役另一台仪器。重新委托的阵列中的一些单独的探测器不再表现良好。这笔资金主要用于更换两个运转不佳的探测器。这将增强整个阵列的性能。衡量这些要素是很重要的。锰是必需的，但过量则是有毒的。在工作场所接触锰、由此产生的骨骼储存水平以及随后可能对健康造成的影响之间的关系根本不为人所知。同样，铝是有毒的，对正常的骨骼功能有有害影响。关于铝是否在阿尔茨海默氏症的病因中起作用，也存在持续的争议。能够测量这些元素在骨骼中的储存水平将有助于更好地了解这些元素对健康的影响，进而防止伤害。

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.