The Initial Testing of DustBuster

• Main Authors: En-Chuan Huang, 黃恩泉
• Other Authors: Typhoon Lee
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/46756964790604763702

碩士 === 國立臺灣大學 === 物理研究所 === 97 === To fit the need of best exploitation of one-of-a-kind tiny (several μms) pre-solar dust grains, we have finished the construction of DustBuster, a new generation of Secondary Neutral Time of Flight Mass Spectrometer (TOF-SNMS) based on the design of Argonne National Lab. It aims to analyze large isotope variations expected for pre-solar dust grains in meteorite and in comet sample returned by Star Dust Mission. At a mass resolution around 1000, our useful yield (ions detected/atoms sputtered) has reached nearly 5%, while the design goal is 30% and the best achieved so far was 20 % in a similar instrument. Therefore, some further fine tuning is needed to achieve higher sensitivity. We have tested several terrestrial samples, such as Mo, Ti, Ni, ilmenite, titanite, rutile, pyrite, forsterite and melilite. We have also attempted to analyze our first meteorite sample. In our best cases in ilmenite, isotopic variation in 46TiO/48TiO the within run (1000 sec) scatter was only 0.7% (1σ), which is within factor of 2 of statistics limit. And the reproducibility in the case of 46TiO can be as good as ≦1%. However, hydride/hydroxide and low-level contamination problems wait still to be solved.