Nuclear shape and structure in neutron-rich 110,111Tc

Journal Article · Thu Feb 02 00:00:00 EST 2006 · Physical Review C

DOI:https://doi.org/10.1103/PhysRevC.74.024308· OSTI ID:901674

Luo, Y X; Hamilton, J H; Rasmussen, J O; Ramayya, A V; Stefanescu, I; Hwang, J K; Zhu, S J; Gore, P M; Jones, E F; Fong, D; Wu, S C; Lee, I Y; Ginter, T N; Ter-Akopian, G M; Daniel, A V; Stoyer, M A; Donangelo, R; Gelberg, A

The structure of Tc nuclei is extended to the moreneutron-rich regions based on measurements of prompt gamma rays from thespontaneous fission of 252Cf at Gammasphere. The level scheme of N=67neutron-rich (Z=43) 110Tc is established for the first time and that of111Tc is expanded. The ground-state band of 111Tc reaches theband-crossing region and the new observation of the weakly populatedalpha = -1/2 member of the band provides important information ofsignature splitting. The systematics of band crossings in the isotopicand isotonic chains and a CSM calculation suggest that the band crossingof the gs band of 111Tc is due to alignment of a pair of h11/2 neutrons.The best fit to signature splitting, branching ratios, and excitations ofthe ground-state band of 111Tc by RTRP model calculations result in ashape of epsilon2 = 0.32 and gamma = -26 deg. for this nucleus. Itstriaxiality is larger than that of 107Tc, to indicate increasingtriaxiality with increasing neutron number. The identification of theweakly-populated "K+2 satellite" band provides strong evidence for thelarge triaxiality of 111Tc. In 110Tc the four lowest-lying levelsobserved are very similar to those in 108Tc. At an excitation of 478.9keV above the lowest state observed, ten states of a delta I = 1 band areobserved. This band is very analogous to the delta I = 1 bands in106,108Tc, but it has greater signature splitting at higherspins.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Director. Office of Science. Office of AdvancedScientific Computing Research. Office of Nuclear Physics,DE-FG05-88ER40407, DE-AC02-05CH11231, DE-AC-99ID13727, W-7405-ENG48; Major State Basic Research Development Program G2000077400; ChineseNational Natural Science Foundation 10375032
• DOE Contract Number: DE-AC02-05CH11231
• OSTI ID: 901674
• Report Number(s): LBNL-59476; R&D Project: NOXRAS; BnR: KB0401024; TRN: US0702655
• Journal Information: Physical Review C, Vol. 74; Related Information: Journal Publication Date: 2006
• Country of Publication: United States
• Language: English

Related Subjects

73
71
ALIGNMENT
BRANCHING RATIO
CHAINS
ENERGY LEVELS
EXCITATION
NEUTRONS
NUCLEI
SHAPE
SPONTANEOUS FISSION
Fission Gamma Spectroscopy Triaxial Rotational Bands