Yoshihiro Yamato

Hydrogen analysis of mineral samples at University of Tsukuba

This study reports the present status of our work on the hydrogen analysis of mineral and rock samples. The preparation of a standard material by means of ion implantation, a method of its calibration and the application of the method are described. The number of hydrogen atoms per unit volume in the standard material can be determined from the simultaneous observation of α-particles, γ rays and α–γ coincidence events for the 1H(19F,αγ) reaction at the 16.44 MeV resonance energy. The hydrogen content in a natural obsidian determined with the method mentioned above is in agreement with that obtained by FTIR. A heavy-ion microbeam system under construction, which consists of a Russian-type quadrupole magnet for beam focusing, a beam defining slit system and a γ-ray detector, is also described.

Lamb-shift Polarized Ion Source at UTTAC

The Lamb-shift polarized ion source (PIS) was installed as one of the ion sources for the 12UD Pelletron tandem accelerator at the University of Tsukuba Tandem Accelerator Complex (UTTAC) in 1976. The PIS makes it possible to produce highly polarized negative proton and deuteron beams. However, the Great East Japan Earthquake on 11 March 2011 seriously damaged not only the accelerator but also the PIS. Following the disaster, it was decided that the PIS should be reconstructed and used as the ion source for the newly designed 6 MV tandem accelerator. Main components including the duoplasmatron chamber and spin filter were reused, while other components including the accelerator tubes and some beam ducts were newly produced. After the reconstruction of the PIS, we attempted to generate polarized beams and measure the polarization. Recently, we attempted to produce unstable nuclei with the polarized proton beam for measurements of nuclear moments of unstable nuclei.