Research on concentrations and isotopic abundances of retractory siderophile elements in Ca, Al-rich inclusions and estimation of chemical and physical conditions of the primitive solar nebula

为了估算原始太阳星云的化学和物理条件，对阿连德CV3球粒陨石中的富钙、铝包裹体进行了研究。建立了难熔亲铁元素的定量分析和同位素比值测定方法，并进行了灭绝核素的寻找。从国家科学博物馆收藏的3个阿伦德陨石标本中分离出3个含LCM半径球体的富钙铝包裹体，其中1个为粗粒包裹体，经扫描电子显微镜-能谱分析，1个为黄长石和尖晶石的A型包裹体，另一个包裹体可能为C型包裹体，其原因是斜长岩的丰度较高；另一种可能是B型球粒陨石，用广岛大学的SIMS，在C型包裹体的斜长岩中观察到了由于消失的核素Al-26而产生的过量的Mg-26，在H球粒陨石的酸溶组分中检测到了痕量的消失的核素Cs-135。必须监测难治性亲铁元素的敏感性变化，并在Os的测量中观察到严重的记忆效应。对于铂族元素和其他亲铁元素的负热电离质谱学，与KCJ教授合作，研究了从混合溶液中形成负热离子的基本行为。Heumann在美国美因茨大学使用铂单丝法，从相同数量的元素产生的负热离子强度是Re&Gt；Os&Gt；Ir-Ru&Gt；Mo。Re灯丝法可以用来更好地电离W和Mo。

In order to estimate chemical and physical conditions of the primitive solar nebula, Ca, Al-rich inclusions in the Allende CV3 chondrite were investigated. Methods for quantitative analysis and isotopic ratio measurement of refractory siderophile elements were developed and a search for extinct nuclides was performed.Three Ca, Al-rich inclusions including a lcm-radius spherule were separated from three specimens of the Allende meteorite in the collection of the, National Science Museum A11 of them are coarse-grained inclusions and, from observation using SEM-EDX, one is classified as a Type A inclusion with melilite and spinel ; another inclusion is probably a Type C because of high abundance of anorthite ; the other could be a Type B Using a SIMS at Hiroshima University, Mg-26 excesses due to the extinct nuclideAl-26 were observed in anorthite of the Type C inclusion Also, a trace of the extinct nuclide Cs-135 was detected in an acid-soluble fraction in an H chondriteMethods for quantitative analysis of refractory siderophile elements using an ICP-MS were explored in addition to the well-developed NAA methods. Change of sensitivities of the refractory siderophile elements had to be monitored and severe memory, effects were observed at the measurements of Os. For the negative thermal ionization mass spectrometry of the platinum group elements and other siderophile elements, basic behaviors of formation of negative thermal ions from a mixed solution were investigated in collaboration with Prof. K CJ. Heumann at the University of Mainz Using a Pt single filament method, the intensities of negative thermal ions from the same amount of elements were Re > Os > Ir -- Ru > Mo The Re filament method could be used for better ionization of W and Mo.