Abundance of nuclei with Z greater than 52 in galactic cosmic rays - Long-term averages based on studies of pallasites

Analysis of the results of calibrating meteoritic olivine crystals with238U nuclei at the Bevalac accelerator

“…In particular, the abundance of Th-U nuclei relative to Fe nuclei was obtained equal to (1-2)x 10 -v, and 4x 10 -2 relative to Pt-Pb [15,16,19]. These values correspond reasonably well to the known Solar system abundances [20].…”

“…Such a high track density indicates that in these crystals the Th-U nuclei track density can reach 102-103 tr.cm -3 [15,16].…”

“…The detailed measurements of the track density due to Fe group nuclei performed in crystals from 16 pallasites led to the choice of the pallasites Marjalahti and Eagle Station as most suitable objects for further studies [15,16].…”

“…In spite of all the difficulties mentioned above, at the first stage of these investigations the preliminary data on the abundaneies of cosmic ray nuclei from Sn to Pt-Pb and Th-U relative to Fe group nuclei and on the energetic spectra of all the nuclei of this group (from Fe to U) were obtained [15,16,19].…”

Production profile of cosmogenic 53Mn in the Marjalahti pallasite

“…Marjalahti has been studied in great detail for cosmic ray tracks [Otgonsuren et al, 1976;Kolesnikov et al, 1977]. Using these data and the statistical method of Gupta and Lal [1978] we have calculated the preatmospheric radius of the Marjalahti meteorite to be 20 cm (N. Bhandari et al, unpublished data, 1979).…”