共查询到20条相似文献,搜索用时 15 毫秒
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High-spin states in 169Re were studied and resulted in the identification of a strongly coupled band based on the 9/2-[514] Nilsson state and a decoupled band built on the h9/2 intruder proton orbital (nominally 1/2-[541]). The cranked shell nodel calculations present configuration-dependent deformations that can explain the different band crossing frecpiencies. The experimental 9/2-[514] band in Re shows the largest signature splitting at low spin among the known odd mass Re isotopes. After the alignment of a pair of the i13/2 neutrons, the phase of the splitting is inverted with a significantly reduced amplitude. Additionally, a three-quasipariticle band was observed and assigned to be built likely on the π9/2-[514]⊙AE configuration. 相似文献
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High-spin level structure of 188Au has been studied via the 173Yb(19F, 4nγ) reaction using techniques of in-beam γ-ray spectroscopy. Based on the experimental results, the level scheme of 188Au has been revised significantly. The previously reported positive parity levels have been modified and a new 20+ level was proposed to feed the 18+ states via two low-energy transitions. The existence of the 20+ and the level structures above it are similar to those in the neighboring odd-odd 190,192Au,therefore, the π h_{11/2}^{-1}\otimes \upnu i_{13/2}^{-2} h_{9/2}^{-1} configuration was assigned to the 20+ state. 相似文献
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张玉虎郭松 周小红马龙 郭文涛Oshima M. Toh Y. Koizumi M. Osa A. Kimura A. Hatsukawa Y. Sugawara M. Kusakari H. 《中国物理快报》2007,24(5):1203-1206
High spin states in ^174Re are investigated via the ^152Sm(^27 AL,5nγ)^174Re reaction and γ - γ coincidence relationships are analysed carefully. A new band is identified due to its spectroscopic connection with the known π1/2^-[541] × ν1/2^-[521] band. This band is proposed to be the ground-state band built on the π1/2^-[541]× ,ν5/2^-[512] configuration in view of the low-lying intrinsic states in the neighbouring odd-mass nuclei. It is of particular interesting that the new band exhibits a phenomenon of low-spin signature inversion, providing a new situation for theoretical investigations. 相似文献
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High-spin states in 179Pt have been studied experimentally using the 149Sm(35Cl, p4n) fusion-evaporation reaction at beam energies of 164—180MeV. Measurements of γ-ray excitation function, X-γ coincidences and γ-γ-t coincidences were carried out with 13 BGO(AC) HPGe and 3 LOAX detectors. Based on the measured results, three rotational bands built on intrinsic states assigned to the 1/2-[521], 5/2-[512] and 7/2+[633] Nilsson configurations have been established for 179Pt. It has been observed that the aligned angular moment in the 1/2-[521] band increases suddenly around hω=0.27MeV. The big signature splitting has been observed in the 7/2+[633] band. These phenomena are discussed by referring to the systematics of the level structure in the Pt isotopes and isotones of 179Pt. 相似文献
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张玉虎郭松 周小红马龙 Oshima M. Toh Y. Koizumi M. Osa A. Kimura A. Hatsukawa Y. Sugawara M. Kusakari H. 《中国物理快报》2005,22(11):2788-2791
High spin states in ^174Re have been investigated via the ^152Sm (^27 Al, 5nγ) ^174Re reaction. Gamma-ray excitation functions, x-γ and γ-γ coincidences have been measured. Two rotational bands built on the πh9/2 × vi13/2 and πh11/2 × vi13/2 configurations have been identified and extended up to high-spin states. The relative spin and parity of the band levels have been unambiguously fixed due to observations of several inter-band transitions. Both the bands show the low-spin signature inversion, which is consistent with systematic expectations for the high-j two-quasiparticle bands in the A = 170 mass region. 相似文献
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形变双奇核178Ir转动带能级的旋称反转 总被引:1,自引:0,他引:1
张玉虎 T.Hayakawa M.Oshima Y.Toh J.Katakura Y.Hatsukawa M.Matsuda N.Shinohara T.Ishii H.Kusakari M.Sugawara T.Komatsubara 《中国物理 C》2000,24(12):1123-1130
利用152Sm(31P,5nγ)178Ir反应产生并研究了双奇核178Ir的高自旋态.实验中进行了178Ir核的在束γ测量,包括γ射线的激发函数测量、X–γ和γ–γ符合测量.首次建立了双奇核178Ir基于πh9/2νi13/2和πh11/2νi13/2准粒子组态上的转动带能级纲图.发现在低自旋区,两个转动带能级均出现旋称反转.对此核区半退耦带的旋称反转作了简要的分析和讨论. 相似文献
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LI Rong-Jun MA Ying-Jun WU Xiao-Guang ZHANG Yu-Hu ZHU Li-Hua WANG Shou-Yu LI Ming-Fei LIANG Guo-Dong CUI Xing-Zhu LI Xian-Feng ZHAO Guang-Yi LU Jing-Bin 《中国物理C(英文版)》2005,29(1):1-4
Excited states in odd–odd 126I have been studied via the heavy–ion induced fusion–evaporation reaction 122Sn(11B,5n2p) at beam energies of 55 and 60 MeV with beams provided by the HI–13 tandem accelerator of CIAE in Beijing.A level scheme consisting of 20 new γ transitions assigned to 126I is established.The assignment of the established level scheme to 126I is based on the observed coincidences between the newly identified γ–transitions and two previously known cascade γ transitions feeding the ground state of 126I, and supported by a cross measurement using the 124Sn(7lI,5n) reaction performed at UTTAC,Japan.The observed structures of 126I at high spins show typical properties of collective rotation in a deformed nucleus. their possible configurations are discussed briefly on the basis of knowledge from the neighboring nuclei. 相似文献
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YU Hai-Ping GUO Ying-Xiang LEI Xiang-Guo ZHANG Yu-Hu ZHOU Xiao-Hong LUO Peng LIU Min-Liang SONG Li-Tao WANG Hua-Lei XIE Cheng-Ying ZHENG Yong GUO Wen-Tao 《中国物理C(英文版)》2004,28(8):806-809
High spin level structure of doubly odd nucleus 140Pr has been investigated using in beam γ spectroscopy techniques by means of the 130Te(14N,4n)140Pr reaction at beam energy of 58MeV.γ-ray excitation functions,γ-ray singles and γ-γ-t coincidences were measured experimentally.The level scheme of 140Pr,including 27 new levels and 42 new γ-rays,was established for the first time up to 4717.3keV in excitation energy.Based on the measured γ-ray anisotropies,spin values were suggested to the levels in 140Pr.Several quasiparticle configurations are discussed on the basis of systematics in the neighboring odd odd nuclei,and interpreted qualitatively. 相似文献
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189W activities were produced via the 192Os(n, α) reaction using irradiation of isotopically enriched 192Os metallic powder of ~100 mg/cm2 with 14 MeV neutrons. The X-γ and γ-γ coincidence measurements were made so as to obtain γ rays from 189W decay and its coincidence relations. A new simple decay scheme of 189W including three γ rays of 210.2, 229.6 and 260.2 keV is proposed. Two new levels of 189Re at 470.4 and 489.8 keV are assigned. 相似文献
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顾龙 朱胜江 J. H. Hamilton A. V. Ramayya J. K. Hwang 刘少华 王建国 罗亦孝 J. O. Rasmussen 李一阳 丁怀博 李科 徐强 杨韵颐 《中国物理快报》2009,26(9):101-104
The high spin states of a neutron-rich ^107 Tc nucleus are reinvestigated by observing prompt γ-rays from the spontaneous fission of ^252 Cf. The previous level scheme is updated. A collective band based on the π5/2- [303] orbital is confirmed and extended. Inconsistencies in the configuration assignments for a type of positive parity bands of odd-A 105,107,109 Tc in the previous reports are clarified according to the g factor calculations. A new band based on the 1499.5 keV level in ^107Tc is proposed as a two-phonon γ-vibrational band. 相似文献
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Through measuring prompt γ-rays emitted in the spontaneous fission of 252Cf with higher statistic data,level structures in the neutron rich,odd A107Ru nucleus have been re investigated. New level scheme of 107Ru has been established. The ground state band was extended with spin up to 27 2h. The νh11/2 band structure observed in our previous publication has been confirmed and extended. These results clear up the inconsistence between our earlier work and results from another experiment published recently. A collective band built on (9/2-) level has been observed for the first time. Some important features of the level scheme have been discussed. 相似文献
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Ma Yingjun Zhao Guangyi Wang Zhe Zheng Hua Liu Yunzuo Zhou Shangui Wu Xiaoguang Yang Chunxiang 《中国物理C(英文版)》1997,21(11):970-975
Both yrast and 4-quasiparticle bands in 162Lu are established by using in-beam spectroscopy. It is shown that within the framework of cranking shell model,positive deformation can also lead to the low-spin signature inversion in the yrast band in Z=71 odd-odd 162Lu nucleus. 相似文献
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ZHANG Yu-Hu 《中国物理C(英文版)》2002,26(6):582-588
High spin states in deformed odd-odd 180Ir have been investigated using the 154Sm (31P, 5nγ)180Ir reaction through the measurements of excitation functions at 150, 155, 160, 165 and 170 MeV beam energies, K X-γ and γ-γ coincidences at 160 MeV. A new level scheme composed of 5 rotational bands has been established. According to the band structure characteristics and the deduced in band B(M1)/B(E2) ratios, the quasiparticle configurations and spin and parity have been proposed to the observed bands. The neutron AB crossing is observed at hωc≈0.26 MeV for the π1/2-[541]⊙ν1/2-[521] and π1/2-[541]⊙ν5/2-[512] bands. This AB crossing frequency is close to that in the ν5/2-[512] band of 179Os indicating the loss of intruder nature of the π1/2 - orbit. Gradual alignment gain in both the π9/2-[514]⊙ν7/2+[633] and π9/2-ν5/2-[512] bands is observed which is similar to the low spin anomaly in alignment in the πh11/2,πd5/2 and πi13/2 bands of neighboring Ir and Re isotopes. Different alignment properties have been discussed in the framework of cranked shell model, and a larger quadrupole deformation is suggested for the bands with π9/2-[514] orbit involved. 相似文献
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Through measuring high-fold prompt γ- ray coincidence events following the spontaneous fission of 252 Cf with the Gammasphere detector array, new level scheme in the very neutron-rich odd-A 113Ru nucleus has been established. An intruder collective band based on 11/2- level has been identified with spin up to 31/2 k and excitation energy 3.6 MeV. This band most probably originates from vh11/2. intruder orbital. Another collective band probably built on 9/2- level is also observed. Some important characteristics of the collective bands have been systematically discussed. 相似文献
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通过重离子熔合蒸发反应116Cd(27Al, 4n)布居了139Pm的高自旋激发态,用12台高纯锗探测器(HpGe)阵列进行了在束γ-γ 符合测量。 基于γ-γ符合关系及139Pm核已知的能级信息,建立了两条ΔI=1的负宇称带。 利用相邻核能级结构的系统性和依据半经典的核子-核子有效作用的理论模型(SPAC)对这两条带能级结构进行了定量计算, 认为它们属于磁转动带。 High spin states in 139Pm have been studied via the116Cd(27Al, 4n) heavy ion fusion evaporation reaction. The γ-γ coincidences were measured with 12 HpGe detectors. Based on γ-γ coincidence relationships and previously known levels in 139Pm, two ΔI=1 negative parity bands have been established. From the systematic comparison with the neighbouring nuclei and semi classical effective interaction model (SPAC) calculations, the two bands were suggested as magnetic rotational bands. 相似文献
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方永得 张玉虎 M.Oshima Y.Toh 周小红 M.Koizumi A.Osa A.Kimura Y.Hatsukawa T.Morikawa M.Nakamura M.Sugawara H.Kusakari 《中国物理 C》2006,30(2):99-104
利用在束γ谱学实验技术, 通过173Yb(19F,4nγ)反应
布居了188Au的高自旋态, 并对其准粒子带结构进行了研究. 基于实验测量结果, 对原有的双奇核188Au能级纲图做了较大的修改. 通过系统性比较, 对15+以上的能级结构进行了讨论. 相似文献
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The g-factors of the positive parity rotational states up to spin I = 8^+ for the ground state band in even-even nuclei S2Sr have been measured by a transient-magnetic-field ion implantation perturbed angular distribution method. The experimentally measured 9-factors increase with the increasing spin along the band and show that the g9/2 proton aligns only and the alignment starts from I =6^+. The measured g-factors also indicate that the nuclei ^82Sr gain their spins by the quasi-proton alignment at higher spin. 相似文献