Lifetime measurements were made for the nu h(11/2) band in Pd-101, which had been interpreted as a possible antimagnetic rotation band based on the comparison of I - omega behavior with the calculation of a semiclassical particle-rotor model in our previous study. Doppler broadened line shapes were analyzed for the decaying gamma rays in the band following the reaction Zn-68(Cl-37, 1p3n)Pd-101. The semiclassical particle-rotor model was modified to reproduce both the I - omega plot and the B(E2) behavior simultaneously for the antimagnetic rotation bands in Pd and Cd nuclei, for which B(E2) values had been measured so far. Reasonable agreements between the experiment and the calculation were obtained. It is concluded that the lower part of the nu h(11/2) band in Pd-101 can be interpreted as an antimagnetic rotor.

High-spin states of Rh-99 were studied through in-beam gamma-ray spectroscopy by using the reaction Zn-68(Cl-37, alpha 2n). The upper part of the band based on the g(9/2) proton orbital was rearranged in four parallel cascades. Negative parity was tentatively assigned for the side-band that previously had no parity assignment. This negative-parity band was interpreted as having the configuration of pi(g(9/2))(5)nu[(d(5/2)g(7/2))(3)(h(11/2))] and extended up to 51((-))/2, which is possibly a terminating state. The band based on the p(1/2) proton orbital was observed up to 29(-)/2 and its property was compared with those of neighboring odd-Z nuclei from the two different viewpoints, one of which is a weakly deformed soft rotor with spin alignments and the other is vibrational to rotational evolution along the band.

High-spin states of Pd-101 were studied through in-beam gamma-ray spectroscopy by using the reaction Zn-68(Cl-37, 1p3n). The band based on the h(11/2) neutron orbital was extended up to (51(-)/2), and the band based on the d(5/2) neutron orbital was revised. Various transitions decaying to these bands were observed, and consequently several side bands were established. Electric dipole transitions from the nu h(11/2) band to the nu d(5/2) band were also observed. The structure of the nu h(11/2) band is discussed from the viewpoint of antimagnetic rotation based on a semiclassical particle-rotor model by taking neutron alignments into account. The possible existence of octupole correlations is also discussed on the basis of B(E1)/B(E2) ratios for the decays of the nu h(11/2) band.

High-spin states in deformed odd-odd 186Au have been reinvestigated via the 172Yb(19F,5nγ) fusion-evaporation reaction.Detailed analysis of γ-γ coincidence relationships leads to a revised high-spin level scheme for 186Au.New spin values are assigned to the prolate πh9/2i13/2 and πi13/2i13/2 bands in 186Au according to the level spacing systematics as well as the existing knowledge in odd-odd neighboring nuclei.Based on the new spin assignments,both bands exhibit the characteristics of low-spin signature inversion.The properties of signature splitting for the prolate πh9/2i13/2 and πi13/2i13/2 and oblate πh-111/2νi-131/2 bands in Au isotopes have been discussed.A new rotational band built on Ix=(20+) state has been identified and assigned as the oblate πh-111/2  νi-232h-19/12 configuration.

The high-spin level structure of Au-186 is re-investigated by means of in-beam gamma-ray spectroscopy via the Yb-172(F-19, 5n gamma)Au-186 reaction. The oblate bands previously reported are revised and extended to higher-spin states. A new I-pi = (20(+)) excited state has been identified and assigned to the pi h(11/2)(-1) circle times nu i(13/2)(-2)h(9/2)(-1) configuration. The total Routhian surface and cranked shell model calculations suggest that the pi h(11/2)(-1) circle times nu i(13/2)(-2)h(9/2)(-1) band in Au-186 has a non-axial deformation.

A new rotational band has been identified and assigned to 188Au for the first time using the 173Yb(19F,4nγ) reaction at the beam energies of 86 and 90 MeV. This band is proposed to be built on the πh 9/2 ⊗ νi 13/2 configuration by comparing the band properties with known bands in neighboring nuclei. The prolate-to-oblate shape transition through triaxial shape has been proposed to occur around 188Au for the ηh 9/2 ⊗ νi 13/2 bands in odd-odd Au isotopes on the basis of total Routhian surface (TRS) calculations.

The high-spin level structure of {sup 188}Au has been investigated via the {sup 173}Yb({sup 19}F,4n{gamma}) reaction at beam energies of 86 and 90 MeV. The previously reported level scheme has been modified and extended significantly. A new I{sup {pi}}=20{sup +} state associated with {pi}h{sub 11/2}{sup -1} x {nu}i{sub 13/2}{sup -2}h{sub 9/2}{sup -1} configuration and two new rotational bands, one of which is built on the {pi}h{sub 9/2} x {nu}i{sub 13/2} configuration, have been identified. The prolate-to-oblate shape transition through triaxial shape has been proposed to occur around {sup 188}Au for the {pi}h{sub 9/2} x {nu}i{sub 13/2} bands in odd-odd Au isotopes. Evidence for {pi}h{sub 11/2}{sup -1} x {nu}i{sub 13/2}{sup -1} structure of nonaxial shape with {gamma}\u003c-70 deg. has been obtained by comparison with total Routhian surface and cranked-shell-model calculations.

对149Sm(27Al,4n)172Re反应产生的172Re在束γ的实验数据进行了重新分析,新发现了可归属于172Re的3个转动带,由此建立了由6个转动带构成的172Re高自旋态能级纲图。依据相邻核的带结构知识和推转壳模型分析方法,对新发现的3个转动带的准粒子组态进行了指定,讨论了它们的转动特征。

Experiments based on the isomer-spectroscopy method were performed using the secondary beam line at RCNP, Osaka University. Recently, a new γ-ray spectroscopy method was established using fusion reaction induced by low-energy RI beam. This method enables us to study high-spin states of nuclei in wider mass region where it is difficult to populate them by using the combination of stable beams and stable targets. This method works well although low production of nuclei, because (1) the combination of beams and targets can be selected with large-reaction cross section and (2) high-S/N measurement can be performed by the event-by-event detection to select the events correlated with RI beam, which reduces background γ rays, competing with γ rays emitted from fusion products. As the first step, high-spin states of 142 Pr were studied using fusion reaction induced by low-energy 17 N RI beam. Large cross section was obtained by the 130 Te (17 N ,5 n ) reaction with 4.9 MeV/u 17 N beam. Event selection, which was carried out by the event-by-event detection with low-beam intensity of 2×104 pps, enables high-S/N measurement.

We have re-analyzed the experimental data of in-beam γ spectroscopy for 172Re via the 149Sm(27Al,4n)172Re reaction.Three rotational bands have been newly found and assigned to 172Re.A new level scheme of 172Re,consisting of 6 bands,is thus presented.Based on the existing knowlegde from the neighboring nuclei and the cranked shell model,the quasiparticle configurtions have been assigned to the 3 newly observed bands and their structure properties have been dicussed.

A rotational band with five γ-ray transitions ranging from 2+ to 12+ states was identified in 40Ar. This band is linked through γ transitions from the excited 2+, 4+ and 6+ levels to the low-lying states; this determines the excitation energy and the spin–parity of the band. The deduced transition quadrupole moment of 1.45−0.31+0.49±0.15 eb indicates that the band has a superdeformed shape. The nature of the band is revealed by cranked Hartree–Fock–Bogoliubov calculations and a multiparticle–multihole configuration is assigned to the band.

The high-spin level structure of Au-188 has been investigated via the Yb-173(F-19,4n gamma) reaction at beam energies of 86 and 90 MeV. The previously reported level scheme has been modified and extended significantly. A new I-pi = 20(+) state associated with pi h(11/2)(-1) circle times nu i(13/2)(-2)h(9/2)(-1) configuration and two new rotational bands, one of which is built on the pi h(9/2) circle times nu i(13/2) configuration, have been identified. The prolate-to-oblate shape transition through triaxial shape has been proposed to occur around Au-188 for the pi h(9/2) circle times nu i(13/2) bands in odd-odd Au isotopes. Evidence for pi h(11/2)(-1) circle times nu i(13/2)(-1) structure of nonaxial shape with gamma < -70 degrees has been obtained by comparison with total Routhian surface and cranked-shell-model calculations.

High spin states of Dy-144 have been studied through in-beam gamma-ray spectroscopy by using the reaction Mo-92(Fe-56,2p2n). It has been found that the continuation of the ground-state band forks into three Delta I=2 bands above the 8(+) state. This forking has been attributed to the alignments of pi h(11/2)(2) or nu h(11/2)(-2) configurations with the help of the systematics in neighboring nuclei. Additionally a negative-parity sideband of Delta I=2 cascades has been observed to start from the 5((-)) state and continue to a dipole band above the (13(-)) state through another negative-parity sideband of Delta I=2 cascades in between. These structures have been discussed from the viewpoint of a competition between "Magnetic Rotation" and "Anti-magnetic Rotation" based on a classical particles-plus-rotor model. .

Modest spin states in neutron-rich W-187 have been populated by using a W-186(O-18,O-17) one-neutron transfer reaction. Negative-parity bands previously known are extended to higher spin, and two positive-parity bands are newly identified. Configurations based on nu i(13/2) orbitals are assigned to these bands from an analysis of the level energy systematics as well as the g factors derived from in-band branching ratios.

. Excited states in neutron-rich 185 Ta have been populated following the one-proton pickup reaction of 186 W( 18 O, 19 F). In-beam γ -rays were measured in coincidence with scattered particles detected by a high-resolution Δ E - E Si telescope for reaction channel selection. Several low-lying levels including a T 1/2 = 0.9(3) μs isomer at 406 keV have been identified. A spin assignment of I = 3/2 and the 1/2 + [411] Nilsson configuration are given to the isomer in comparison with the level energy systematics and the isomer decay rates in the region.

Excited states in neutron-rich Ta-185 have been populated following the one-proton pickup reaction of W-186(O-18, F-19). In-beam gamma-rays were measured in coincidence with scattered particles detected by a high-resolution Delta E-E Si telescope for reaction channel selection. Several low-lying levels including a T-1/2 = 0.9(3) mu s isomer at 406 keV have been identified. A spin assignment of I = 3/ 2 and the 1/ 2(+)[ 411] Nilsson configuration are given to the isomer in comparison with the level energy systematics and the isomer decay rates in the region.

We made three kinds of measurements at E-p=13 MeV; i) D(p,pp)n experiment at ppFSI, ii) D(p,p)pn experiment at theta(p)=10 degrees - 60 degrees, and iii) D(p,pp)n experiment at many angle pairs around the space star. For an easy estimate of Coulomb effects in pd breakup reaction, we proposed Watson- Migdal & Faddeev calculation which was found to give nearly the same results as the pd calculation by Deltuva et al.. Cross sections of i) and ii) are well reproduced by the pd calculation, however, 10-15% discrepancy has been found between the cross section of iii) and the calculation.

. Excited states in neutron-rich 188 W have been populated using a 186 W( 18 O, 16 O) reaction. In-beam γ-rays were measured in coincidence with scattered particles detected by a high-resolution Δ E - E Si telescope. In this experiment, the ground-state band has been identified up to I π = 8 + . The γ band, the K π = 2 - octupole band, and a 2-quasiparticle state were also observed. The results are compared with predictions of self-consistent HFB cranking calculations and blocked-BCS multi-quasiparticle calculations.

The high-spin states of Ho-150 have been studied by the Pr-141(O-16,7n)Ho-150 reaction at a beam energy of 165 MeV using techniques of in-beam gamma-ray spectroscopy. Measurements of gamma-gamma-t coincidences were performed. Based on the coincidence relations of gamma rays, a level scheme was constructed up to 11.25 MeV. The excitation energy of high-spin isomer was determined to be 8.412 MeV with a half-life of 787 +/- 36 ns. The experimental results were compared with deformed independent particle model (DIPM) calculations. The excitation energy of the state with the possible configuration of the high-spin isomer in Ho-150 was discussed.

Search for low-spin signature inversion in the pi i(13/2) circle times nu i(13/2) bands in odd-odd Au-182,Au-184,Au-186 has been conducted through the standard in-beam gamma-spectroscopy techniques via the Sm-152(Cl-35,5n) Au-182, Yb-172(F-19,5n) (186)An, and Tb-159(Si-29,4n) (184)An reactions, respectively. The pi i(13/2) circle times nu i(13/2) bands in these three nuclei have been identified and extended up to high-spin states. In particular, the inter-band connection between the pi i(13/2) circle times nu i(13/2) band and the ground-state band in Au-184 has been established, leading to a firm spin-and-parity assignment for the pi i(13/2) circle times nu i(13/2) band. The low-spin signature inversion is found in the pi i(13/2) circle times nu i(13/2) bands according to our spin-assignment and-the signature crossing observed at high-spin states.