Plasma Chemical Release of Xenon from the Allende Meteorite

Recent advances in plasma chemistry (1-3) have yielded impressive results and hold great promise for meteoritic studies. Our initial ex­periments (4, unpublished data) indicate that low temperature oxygen plasmas may be effective in extracting noble gases from cosmological samples. One notable advantage is that the noble gases are extracted at temperatures ≤ 250 °C. This reduces background problems associated with the high temperatures necessary for complete gas extraction in ultra-high vacuum heating. Additionally, problems of high temperature diffusive mixing of the component gases are alleviated. Furthermore, the oxygen plasma releases the noble gases from the carbonaceous car­ rier(s), via oxidation of the carrier to CO(g), C02(g) and H20(g), before significant gas release begins from the other components of the sample. This allows the separation and measurement of the noble gases from the carbonaceous carrier as well as the rest of the meteorite in a single sample. Presented at the 54th Annual Meeting of the Meteoritical Society