Application of Nuclear Chemistry in the Study of the Universe

Abstract

Isotopic compositions of the strange Xenon components-HL and the s-type xenon can be explained in a straightforward manner as due to the alteration of the isotopic composition of xenon caused by a combined effect of (a) mass-fractionation, (b) spallation and (c) stellar-temperature neutron-capture reactions. As much as 42.49% of total ¹³⁶Xe (Σ ¹³⁶Xe) found in the Allende diamond inclusions is ²⁴⁴Pu fission xenon (^136fXe) and the trapped xenon is severely mass-fractionated in such a manner that the lighter xenon isotopes are systematically depleted relative to the heavier isotopes. The relative abundances of ¹³⁰Xe and ¹³²Xe in the trapped xenon component are both markedly enhanced indicating that it was irradiated with a total flux of 1.2·10²³ n·cm^-2 of stellar-temperature (10 keV) neutrons. The xenon found in the s-type xenon, on the other hand, resemble that of the atmospheric xenon irradiated with a total flux of about 6.0·10²³ n·cm^-2 of 10 keV neutrons. These results indicate that we are seeing here the effects of nuclear processes occurring inside of a star, such as the exploding supernova.