FUKUDA Mitsunori Graduate School of Science, Osaka University, Associate Professor, 大学院・理学研究科, 助教授 (50218939)
MATSUTA Kensaku Graduate School of Science, Osaka University, Associate Professor, 大学院・理学研究科, 助教授 (50181722)
NOJIRI Yoichi Faculty of Engineering, Kochi Univ. of Technology, Prefessor, 工学部, 教授 (90028233)
MIHARA Mototsugu Graduate School of Science, Osaka University, Research Associate, 大学院・理学研究科, 助手 (60294154)
|Budget Amount *help
¥17,200,000 (Direct Cost: ¥17,200,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥6,400,000 (Direct Cost: ¥6,400,000)
Fiscal Year 1996: ¥10,200,000 (Direct Cost: ¥10,200,000)
We put the new nuclear quadrupole resonance technique (by means of asymmetric β decay) to practical use, introducing artificial manipulation of the nuclear spin into the nuclear magnetic resonance technique by means of asymmetric β decay (β-NMR) on the spin polarized short lived nuclei.
(1) We developed many kinds of relatively light β-NMR probe nuclei. The nuclear spins of ィイD18,12ィエD1B, ィイD19ィエD1C, ィイD112,16ィエD1N, ィイD113ィエD1O, ィイD120,21ィエD1F, ィイD123ィエD1Mg, ィイD127ィエD1Si, ィイD135ィエD1Ar, ィイD139ィエD1Ca, were successfully polarized in high energy projectile fragmentation process, by selecting emission angle of the fragments. In addition, we investigated the nuclear spin polarization mechanism of ィイD120ィエD1F, ィイD119ィエD1O, ィイD18ィエD1Li, ィイD116ィエD1N in low energy nuclear reactions, and determined the optimum condition of the production of these polarized probe nuclei.
(2) We put the new nuclear quadrupole resonance technique to practical use. We developed the highly efficient nuclear quadrupole r
esonance and the artificial manipulation of nuclear spin, by applying rf magnetic fields on the NMR resonance frequencies split under the quadrupole interaction. To realize this technique, we introduced the high speed tuning system by the switching of the vacuum capacitors. We applied this technique to the ィイD112ィエD1B (nuclear spin I = 1), ィイD123ィエD1Mg, ィイD135ィエD1Ar, ィイD139ィエD1Ca (I = 3/2), ィイD18ィエD1B, ィイD116ィエD1N (I = 2), ィイD119ィエD1O, ィイD121ィエD1F, ィイD127ィエD1Si (I = 5/2), and ィイD141ィエD1Sc (I = 7/2).
(3) We elucidated the electric field gradients and the electronic structures inside crystals. Comparing experimental electric field gradients and the first principle calculations of the electron band structure, we found the importance of the charge state of the impurities and local lattice relaxation.
(4) Thus developed nuclear spin manipulation technique was applied to the mutual conversion between nuclear spin polarization and alignment. We succeeded in the production of nuclear spin alignment in ィイD18ィエD1B, ィイD120ィエD1F, and ィイD141ィエD1Sc, and observed the alignment correlation terms in β-ray angular distributions precisely. Less