Stable chromium nuclides produced by cosmic rays were measured by the surface ionization method applied with a chromium fraction extracted from several iron meteorites. A solid source mass spectrometer, MS-5, manufactured by AEI, England, was used for the determination of theisotopic ratios. It was found to be useful to apply the single filament technique using a tungsten ribbon. Repeated experiments using a microgram quantity of reagent chromium gave satisfactory small deviation throughout the course of this work which extended more than one year. The result with the reagent was in good agreement with natural chromium isotopic composition that appeared in literature. A marked enrichment of
54Cr,
53Cr and
5050;Cr due to cosmic ray products could be observed in chromium isolated by solvent extraction from meteorite solutions. An isotopic dilution analysis using enriched
50Cr or
52Cr was made to obtain absolute content of these cosmogenic nuclides. The overall contents of
53Cr and
54Cr were found to be in the range of13-25ppb in several meteorites. The experimental procedure is described in detail here.
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