Nuclear shape and structure in neutron-rich {sup 110,111}Tc
- Physics Department, Vanderbilt University, Nashville, Tennessee 37235 (United States)
- Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
- KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium)
- Physics Department, Tsinghua University, Beijing 100084 (China)
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China)
- Mississippi State University, Drawer 5167, Mississippi State, Mississippi 39762 (United States)
- Flerov Laboratory for Nuclear Reactions, JINR, Dubna (Russian Federation)
- Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
- Universidade Federal do Rio de Janeiro, CP 68528, RG (Brazil)
- Institut fuer Kernphysik, Universitaet zu Koeln, D-50937, Cologne (Germany)
The high-spin nuclear structure of Tc isotopes is extended to more neutron-rich regions based on the measurements of prompt {gamma} rays from the spontaneous fission of {sup 252}Cf at the Gammasphere. The high-spin level scheme of N=67 neutron-rich {sup 110}Tc (Z=43) is established for the first time, and that of {sup 111}Tc is extended and expanded. The ground band of {sup 111}Tc reaches the band-crossing region, and the new observation of the weakly populated {alpha}=-1/2 member of the band provides important information on signature splitting. The systematics of band crossings in the isotopic and isotonic chains and a CSM calculation suggest that the band crossing of the ground band of {sup 111}Tc is due to alignment of a pair of h{sub 11/2} neutrons. The best fit to signature splitting, branching ratios, and excitations of the ground band of {sup 111}Tc by the rigid triaxial rotor plus particle model calculations result in a shape of {epsilon}{sub 2}=0.32 and {gamma}=-26 deg. for this nucleus. Its triaxiality is larger than that of {sup 107,109}Tc, which indicates increasing triaxiality in Tc isotopes with increasing neutron number. The identification of the weakly populated K+2 satellite band provides strong evidence for the large triaxiality of {sup 111}Tc. In {sup 110}Tc, the four lowest-lying levels observed are very similar to those in {sup 108}Tc. At an excitation of 478.9 keV above the lowest state observed, ten states of a {delta}I=1 band are observed. This band of {sup 110}Tc is very analogous to the {delta}I=1 bands in {sup 106,108}Tc, but it has greater and reversal signature splitting at higher spins.
- OSTI ID:
- 20863704
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 74, Issue 2; Other Information: DOI: 10.1103/PhysRevC.74.024308; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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