Search

Based on the technique of fragment‐induced spin polarization combined with the β‐NMR method, a series of experiments has been carried out at RIKEN for the nuclear‐moment measurement of light unstable nuclei. The measurement will be extended further in the RIKEN RIBF project, where radioactive‐isotope beams in the medium‐ and heavy‐mass regions will be produced at higher energies and with higher intensities compared with the RARF facility. Measurements of the isomeric‐state nuclear moments of unstable nuclei will be started with BigRIPS by utilizing fragment‐induced spin‐orientation phenomena. Also, an upgrade program of the existing fragment separator RIPS is proposed in the phase‐II program of RIBF. Then, intense beams will be delivered to RIPS at E ∼ 115 A MeV. This energy region is useful, not only because spin orientation is produced in the PF reaction but also they can be implanted into sample materials with limited thickness.

資料番号: AA0047272013

資料番号: AA0047272012

資料番号: AA0045918014

For the first time, we obtained the g factor for the ground state of {sup 23}Al by use of a {beta}-NMR measurement. {sup 23}Al has a small proton separation energy and is a potential proton-halo candidate. The obtained g factor, vertical bar g vertical bar =1.557{+-}0.088, clearly shows the spin and parity, J{sup {pi}}=5/2{sup +}, for {sup 23}Al, which is the same as that of its mirror partner, {sup 23}Ne. The possible nuclear structure of {sup 23}Al is also discussed.

We have measured the spin polarization of half-metallic Heusler alloy Co_{2}MnSi by the Andreev reflection technique. The differential conductance G(V) of Co_{2}MnSi/Pb junctions was measured in the temperature range between 1.5 K and 10 K. The structure of G(V) became gradually smaller with the increase of temperature and disappeared above the superconducting critical temperature T_{c} of Pb thin films. Temperature dependence of the superconducting energy gap Δ(meV) coincides with that of the Bardeen-Cooper-Schrieffer (BCS) theory. The obtained G(V) was able to be fitted very well by the modified Blonder-Tinkham-Klapwijk (BTK) model up to the T_{C}. We have found the spin polarization of 52.5% for Co_{2}MnSi.