Stabilized power supplies for thermal ionization MS

质量依赖过程和核衰变改变了化学元素钼的七种稳定同位素的相对丰度。 同位素丰度变化的高精度测量提供了独特的线索，这些过程的类型和程度发生在陆地和地外环境。这些信息对于理解产生重元素的基本核过程至关重要。 例如，我们最近从铁陨石获得的数据表明，我们的太阳系是由各种核合成来源的产物形成的。 此外，从世界各地采集的辉钼矿样品的高精度钼同位素丰度数据表明，同位素丰度变化较小但相对显著，与矿体中钼的地质来源和矿物形成温度有关。 Wieser操作的热电离质谱仪最初由美国马里兰州的国家标准与技术研究所设计和建造。 这个有30年历史的仪器于2000年被带到卡尔加里，并在卡尔加里大学和NSERC的支持下投入使用。 在过去五年中，作为国际合作研究项目的一部分，它被广泛用于研究地球和地球外物质中钼同位素丰度的变化。 质谱仪也是培训学生和技术人员的主要工具。 我们的研究目标现在需要最高水平的灵敏度和精确度。 因此，对热电离质谱仪进行战略性电子升级是我们在研究工作中取得进展所必需的。 一些稀有的陨石和十亿年前的矿物样品在达到稳定的仪器操作条件之前无法进行分析。 我们的工作成果将产生新的知识行星物理，核，并可能在地球和外星环境中的生物过程。

Mass dependent processes and nuclear decays alter the relative abundances of the seven stable isotopes of the chemical element molybdenum.  High precision measurements of isotope abundance variations provide unique clues to the types and extents of these processes that occurred in terrestrial and extra-terrestrial environments. This information is critical to understand the fundamental nuclear processes that produce the heavy elements.  For example, our recent data from iron meteorites indicate that our Solar System was formed from the products of diverse nucleosynthetic sources.  In addition, high precision molybdenum isotope abundance data of samples of molybdenite ores collected from around the world show that small but relatively significant isotope abundance variations are correlated with the geological source of the molybdenum in the ore body and the temperature of formation of the mineral. The isotopic composition of molybdenum is measured by specialized mass spectrometric techniques.  Wieser operates a thermal ionization mass spectrometer that was originally designed and built by the National Institute of Standards and Technology in MD, USA.  This 30 year-old instrument was brought to Calgary in 2000 and made operational with support from the University of Calgary and NSERC.  Over the past five years, it has been used extensively for research in molybdenum isotope abundance variations in terrestrial and extra-terrestrial materials as part of international collaborative research projects.  The mass spectrometer is also a major tool for the training of students and technicians.  Our research goals now demand the highest levels of sensitivity and precision.  Therefore, strategic electronic upgrades to the thermal ionization mass spectrometer are necessary for us to make progress in our research efforts.  Several rare meteorite and billion year-old mineral samples cannot be analyzed until stable instrumental operating conditions are achieved.  The outcomes of our work will generate new knowledge of planetary physical, nuclear, and possibly biological processes in terrestrial and extra-terrestrial environments.