Isotopic Fractionations by Low-Energy Ion Implantation: A Possible Solar System Process
Abstract
The isotopic signatures of the noble gases found in planetary atmospheres compared to those in the solar wind have been considered diagnostic of early and ongoing solar system processes. Model explanations for the evolution of terrestrial planets' atmospheres have been numerous, but largely ignored until recently has been the process of low-energy ion implantation. Although low-energy ion implantation was suggested as a factor influencing the evolution of solar system inventories, little work has been carried out regarding the magnitude and relevance of the process, and none was done for Ne or Ar. We confirmed observations by Bernatowicz and Hagee that Kr and Xe implanted in W are isotopically fractionated by 1% to 2% per amu. We further demonstrated that argon is fractionated > 3% per amu; here we report large fractionations for Ne and Ar. The identification of suitable conditions for changing isotopic and elemental signatures of nobles gases is a first step in a search for natural environments where low-energy implantation may have occurred.
- Publication:
-
Lunar and Planetary Science Conference
- Pub Date:
- March 1996
- Bibcode:
- 1996LPI....27.1043P
- Keywords:
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- ATMOSPHERES: PLANETARY;
- FRACTIONATION: ISOTOPIC;
- IONS: IMPLANTATION;
- NOBLE GASES