Abstract
Since 98Tc and 99Tc decay to 98Ru and 99Ru, respectively, via the β- transition, the property of Tc in cosmo- and geochemical fields can be deduced from precise isotopic studies of Ru. Through the approaches on isotopic analyses of Ru in cosmo- and geochemical samples, mass spectrometric techniques with thermal ionization mass spectrometry (TIMS), inductively coupled plasma mass spectrometry (ICP-MS) and secondary ion mass spectrometry (SIMS) have been effectively used. I report herewith the following three topics about the Ru isotopic studies related with the behavior of Tc in cosmo- and geochemical fields: (1) Initial abundance of Tc in the solar system deduced from the Ru isotopic compositions in meteoritic samples, (2) geochemical behavior of fissiogenic Tc in natural fission reactor zones at the 0klo uranium deposit, and (3) a possibility of cosmic-ray produced Tc in terrestrial molybdenite ore bodies.
