Determination of the isotopic composition of trace amounts of actinides in environmental micro-particles by Resonance Ionisation Mass Spectroscopy (RIMS) of sputtered neutrals (SN)

通过溅射中性物质 (SN) 的共振电离质谱 (RIMS) 测定环境微粒中痕量锕系元素的同位素组成

• 批准号: 5426154
• 负责人: Dr. Nicole Erdmann
• 金额: --
• 依托单位: Joint Research Centre Karlsruhe
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5426154?language=en
• 关键词: Determination; isotopic; composition; trace; amounts

Resonance ionisation mass spectroscopy (RIMS) should be developed and applied for the investigation of the isotopic composition of trace amounts of actinides, most important uranium and plutonium, in micron-size particles. Such particles are of high interest in the context of a risk assessment of contaminated areas, nuclear forensic analyses as well as IAEA and Euratom safeguards programs. They usually consist of a uranium oxide matrix, which contains plutonium and americium traces. The determination of the actinide isotopic composition is used to deduce the origin, age and history of the particles. The standard technique for the analysis of small particles, secondary ion mass spectrometry (SIMS), uses ion gun sputtering in combination with mass-selective detection of the secondary ions. It suffers from isobaric interferences (238U/238Pu, 241Am/241Pu). The use of RIMS in combination with ion gun sputtering, post-ionising the sputtered neutrals rather than using the secondary ions, promises to be an elegant tool to overcome the problem of isobaric interference. In addition to extremely high element selectivity when using multi-step resonant ionisation, an increase in efficiency can be expected as ion gun sputtering produces predominantly neutral particles. The proposed set-up requires upgrading the RIMS system the Institut für Kernchemie at the University of Mainz with an ion gun that has a small spot size for sputtering off material from micron-size particles and a new sample stage that allows the handling of particulate samples. A laser system for resonant ionisation and a time-of-flight mass spectrometer for the registration of the created ions already exist. A feasibility study was performed in a previous project.

应发展共振电离质谱法，并将其应用于调查微量锕系元素、最重要的铀和钚在微米级颗粒中的同位素组成。在对受污染地区进行风险评估、核法医分析以及原子能机构和欧洲原子能共同体的保障监督方案方面，这类粒子具有高度的重要性。它们通常由氧化铀基质组成，其中含有钚和镅的痕迹。锕系元素同位素组成的测定可用于推断粒子的起源、年龄和历史。用于分析小颗粒的标准技术，二次离子质谱法（西姆斯），使用离子枪溅射结合二次离子的质量选择性检测。它受到同量异位素干扰（238 U/238 Pu，241 Am/241 Pu）。使用RIMS结合离子枪溅射，后电离溅射的中性粒子，而不是使用二次离子，有望成为一个优雅的工具，以克服等压干扰的问题。当使用多步共振电离时，除了极高的元素选择性之外，可以预期效率的增加，因为离子枪溅射主要产生中性粒子。拟议的设置需要升级RIMS系统，美因茨大学的Institut für Kernchemie拥有一个离子枪，该离子枪具有小的斑点尺寸，用于从微米尺寸的颗粒中溅射出材料，以及一个新的样品台，可以处理颗粒样品。用于共振电离的激光系统和用于记录所产生离子的飞行时间质谱仪已经存在。在以前的项目中进行了可行性研究。