Adsorption and excess fission xenonThe adsorption of Xe and Kr on lunar soil 10084 was measured by a method that employs only very low fractions of monolayer coverage. Results are presented as parameters for calculation of the Henry constant for adsorption as a function of temperature. The adsorption potentials are about 3 kcal/mole for Kr and 5 kcal/mole for Xe; heating the sample in vacuum increased the Xe potential to nearly 7 kcal/mole. Henry constants at the characteristic lunar temperature are about 0.3 cu cm STP/g-atm. These data were applied to consider whether adsorption is important in producing the excess fission Xe effect characteristic of highland breccias. Sorption equilibrium with a transient lunar atmosphere vented fission Xe produces concentrations seven orders of magnitude lower than observed concentrations. Higher concentrations result because of the resistance of the regolith to upward diffusion of Xe. A diffusion coefficient of 0.26 sq cm/sec is estimated for this process.
Document ID
19820048198
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Podosek, F. A. (Washington Univ. Saint Louis, MO, United States)
Bernatowicz, T. J. (Washington Univ. Saint Louis, MO, United States)
Kramer, F. E. (Washington University St. Louis, MO, United States)