Other
Scientific paper
Jul 1993
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993metic..28q.352g&link_type=abstract
Meteoritics, vol. 28, no. 3, volume 28, page 352
Other
Cosmogenic Nuclides, Krypton, Simulation Experiments, Xenon
Scientific paper
The production of krypton from target elements Rb (Rb(sub)2SO(sub)4), Sr (SrF(sub)2), Y, Zr, and of xenon in Ba (Ba glass), La (LaF(sub)3) is studied in a simulation experiment of the galactic cosmic-ray proton bombardment of stony meteoroids in space [1,2]. This investigation is part of the experiment LNS 172 by which a 50-cm-diameter artificial meteoroid (gabbro) was isotropically irradiated at Saturne with 1.6 GeV protons. Measurements of krypton production vs. depth are now complete in the four investigated target elements. In the ^81Kr-^83Kr dating method, the production ratio P(sub)81/P(sub)83 can be evaluated from the cosmogenic spectrum of krypton in the meteorite according to the formula: P(sub)81/P(sub)83=0.95[(^80Kr/^83Kr)(sub)c+(^82Kr/^83Kr)(sub)c]/2 [3] where (^80Kr/^83Kr)(sub)c and (^82Kr/^83Kr)c represent the measured cosmogenic ratios assuming no contribution from (n,gamma) nuclear reactions on Br. Applying this formula to this experiment, a good agreement with the measured production ratio is obtained for Zr and Y targets. On the other hand, this formula overestimates the measured production ratio by 6% for Sr and 15% for Rb. Taking a mean composition of ordinary chondrites [4], the production ratio ^81Kr/^83Kr decreases from the surface to the center by 4% but the value calculated with the formula still exceeds the measured ratio by 7%. The ratio ^78Kr/^83Kr also shows a decrease by 10% from the surface to the center. Variation by 20% of the concentration of target elements can change this ratio by 10%, but, for the same variation, dependence on the target chemistry is less than 4% for ^81Kr/^83Kr. For Xe, depth profiles of production in Ba and La are reported. Production of ^126Xe shows a steep increase from the surface to center by a factor of 1.5 for Ba and of 2 for La. All the production ratios also increase from the surface to the center except ^124Xe/^126Xe, which is decreasing and ^136Xe/^126Xe, which is almost constant. This work was partially supported by C.N.R.S., by IN2P3, and by INSU (Programme National de Planetologie). References: [1] Michel R. et al (1991) Meteoritics, 26, 372a. [2] Gilabert et al. (1992) Meteoritics, 27, 223. [3] Marti K. (1967) Phys. Rev. Lett., 18, 264-266. [4] Wasson J. T. and Kallemeyn G. W. (1988) Phil. Trans. R. Soc., A325, 535-544.
Gilabert Eric
Herpers Ulrich
Lavielle Bernard
Lupke M.
Michel Rigo
No associations
LandOfFree
Production of Krypton and Xenon Isotopes by Galactic Protons does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Production of Krypton and Xenon Isotopes by Galactic Protons, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Production of Krypton and Xenon Isotopes by Galactic Protons will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1072494