Abstract
History of the geochemical research of 130Te double beta decay and the process coming to an idea of primitive Xe are described on the basis mainly of the author's personal experiences. The geochemical research of 130Te-ββ-decay at Osaka University started in 1961, when the author entered the Graduate School of Science of Osaka University, under the supervision of Prof. Kore-ichi Ogata who had designed and installed an ultrahigh-vacuum, high-sensitivity mass-spectrometer at his noble gas laboratory in 1960. The first report that the half-life of 130Te-ββ-decay is 8.2×1020 years was published in 1966. This lifetime was supported by research groups of University of Missouri and confirmed by our new result of 7.9×1020 years, while other research groups of MPI für Physik and Washington University reported the half-lives of 130Te-ββ-decay that are longer by a factor of ∼3. With the excellent noble-gas machine, the author worked well long till 1990 for noble gas researches on meteoritic and terrestrial samples as well as the geochemical research of 128Te- and 130Te-ββ-decays. In the course of a research on meteorite Xe, in 1972, the author had the idea of primitive Xe with which one might be able to understand a mystery in isotope compositions of xenon found among terrestrial atmosphere, solar wind and meteorites. How to work with meteorites is suggested to identify the primitive Xe component in meteorites.
