Advanced instrumentation for accelerator mass spectrometry

用于加速器质谱分析的先进仪器

• 批准号: 327359-2011
• 负责人: Kieser, William
• 金额: $ 2.04万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571997
• 关键词: Advanced; instrumentation; accelerator; mass; spectrometry

The advantages of accelerator mass spectrometry (AMS), in which isotopes and rare atoms can be measured in sub-milligram samples with sensitivities approaching 1 part in a thousand million million, have been largely confined to elements which readily make negative ions and which have isobars that do not, such as Carbon-14 and Iodine-129. For elements that do not meet one or both of these conditions, the development of analytical strategies has been limited and often been confined to the use of larger accelerators (>5 MV). Two innovations begun recently at the IsoTrace Laboratory have demonstrated that the use of AMS can be extended to a much larger fraction of the periodic table. These are: (i) the use of fluoride molecular anions to enhance the production of the negative ions required for AMS and (ii) the use of radio-frequency quadrupole ion guides in cooling and reaction cells to eliminate both atomic and molecular isobars at very low energies - collectively known as the Isobar Separator for Anion (ISA). These techniques are both at a very early stage in their development; much further work is needed to understand the physical processes involved (i) in the formation of the fluoride molecular anions in the complex chemical environment of the ion source and (ii) in the behaviour of the ions as they traverse the intricate electric fields and cooling and reaction gas regions of the ISA. This knowledge is essential for the application of these techniques to different elements and for their use in reliable analytical procedures and equipment. The establishing of the new AMS facility at the University of Ottawa and, while this facility is in preparation, the continued operation of the IsoTrace equipment provide a unique opportunity to carry out this research and to involve in it the participation of graduate students and post-doctoral fellows both in the generation of this knowledge and the implementation of new applications in a multi-disciplinary setting.

加速器质谱法（AMS）的优点可以在其亚密密里法样本中测量，其敏感性接近1亿份的次密封样本，很大程度上仅限于易于产生负的元素，并且具有不可能产生的等值离子，这些元素且具有碳-14和iodine-14和iodine-14和iodine-129。 对于不符合这一条件之一的元素，分析策略的发展受到限制，并且通常仅限于使用较大的加速器（> 5 mV）。 最近在Isotrace实验室开始的两项创新表明，AMS的使用可以扩展到更大的元素周期表。 这些是：（i）使用氟化物分子阴离子来增强AMS所需的负离子的产生，以及（ii）在冷却和反应细胞中使用射频频率四极离子指南，以消除原子和分子异位剂，以消除非常低的能量，以相当低的能量（集体称为Isobar sybarator for Anion）（ISA）（ISA）（ISA）。 这些技术都处于发展的早期阶段。需要进一步的工作来了解离子源的复杂化学环境中氟化物分子阴离子的形成和（ii）在离子行为中所涉及的物理过程（i），因为它们穿越了ISA的复杂电场以及ISA的冷却和反应气体区域。这些知识对于将这些技术应用于不同元素以及它们在可靠的分析程序和设备中的使用至关重要。 在渥太华大学建立了新的AMS设施，尽管该设施正在准备，但同时设备的持续运作为进行这项研究提供了独特的机会，并参与了研究生和博士后研究员的参与，既是该知识的产生，又是在多学科的新应用中实施的。