Pk. Kuroda et Wa. Myers, PU-244 IN THE EARLY SOLAR-SYSTEM AND ISOTOPIC ANOMALIES OBSERVED FOR BARIUM, NEODYMIUM AND CARBON IN CARBONACEOUS CHONDRITES, Radiochimica Acta, 68(3), 1995, pp. 145-153
Large isotopic anomalies have recently been discovered in interstellar
grains of diamond, graphite and silicon carbide isolated from the car
bonaceous chondrites. Re-examination of the existing data for barium a
nd neodymium reveals that the anomalous isotopic compositions of these
elements observed in the meteorite inclusions can be attributed to th
e alterations caused by a combined effect of a) mass-fractionation, b)
spallation and c) 10 keV (stellar temperature) neutron-capture reacti
ons. Spectacular isotopic anomalies observed in graphite and silicon c
arbide grains of the Murchison meteorite can be attributed to the spal
lation reactions induced by the high energy protons near the surface o
f an exploding supernova.