Mass Spectrometric Studies of Undifferentiated Meteorites

各种质谱分析的未分化 陨石将进行研究的条件， 历史的早期阶段所涉及的过程和时间尺度 太阳系和行星体的形成。 的 样品将是完整的岩石和分离的阶段，特别是 磷酸盐 这些分析将包括协调一致的 惰性气体和热发射物质的应用 光谱法 该研究分为三个相关的 项目：1）将尝试确定宇宙 基于裂变径迹分析的Pu-244丰度 未分化陨石; 2）Rb，Sr和Sr-87/Sr-86 低Rb/Sr相的钙钛矿将被确定， 确定Sr-87/Sr-86的初始比例， 这些陨石的“变质”持续时间，3）稀有气体 将使用同位素测量陨石的丰度 稀释，而不是传统的峰高比较 法 这应该给出一个数量级 提高准确性。 PI将在这些方面进行合作 与斯克里普斯大学的卢格迈尔、加州理工学院的伯内特和 在巴黎的朋友。

A variety of mass spectrometric analyses of undifferentiated meteorites will be conducted to study the conditions, processes and timescales involved in the early history of the solar system and in the formation of planetary bodies. The samples will be both whole rock and seperated phases, notably phosphates. The analyses will include coordinated application of both noble gas and thermal emission mass spectrometry. The research is organized into three related projects: 1) An attempt will be made to determine the cosmic abundance of Pu-244 based on analysis of fission Xe in undifferentiated meteorites, 2) Rb, Sr, and Sr-87/Sr-86 in low Rb/Sr phases of chondrites will be determined in order identify initial Sr-87/Sr-86 ratios and constrain the duration of 'metamorphism' for these meteorites, 3) Noble gas abundances in chondrites will be measured using isotope dilution rather than the conventional peak-height comparison technique. This should give an order-of-magnitude improvement in accuracy. The PIs will collaborate in these analyses with Lugmair at Scripps, Burnett at Cal Tech, and Pellas at Paris.