论文部分内容阅读
我院改进前的缓发中子测铀装置10次循环活化分析的探测极限为5ppb左右,这对植物、牧草、粮食等样品的分析是有效的,然而对高纯物质的分析(如单晶硅中的铀的分析)就不够了。据国外报道大规模集成电路存贮器的单晶硅片要用高纯的单晶硅,否则会出现软错误。其原因是单晶硅片中的~(238)在天然衰变时会释放出几个MeV能量的α粒子,它破坏了存贮器里的讯息。高纯单晶硅的钠含量比普通单晶硅(ppb级)低2—3个数量级。为了能测定高纯物质中的铀含量,对测量装置和方法作了一些改进,使灵敏度提高了约一个数量级。
In our hospital, the detection limit of 10 cycles of activation assay for the delayed neutron-measuring uranium unit was about 5 ppb, which is valid for the analysis of samples of plants, pastures and grains. However, the analysis of high-purity substances Uranium in silicon analysis) is not enough. According to foreign reports of large-scale integrated circuit memory monocrystalline silicon to use high purity silicon, otherwise there will be a soft error. The reason for this is that ~ (238) in monocrystalline silicon releases several MeV-energy alpha particles when it decays naturally, destroying the memory message. The sodium content of high-purity monocrystalline silicon is 2-3 orders of magnitude lower than ordinary monocrystalline silicon (ppb grade). In order to determine the uranium content of high purity material, some improvements have been made to the measuring device and method, increasing the sensitivity by about one order of magnitude.