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

Journal Article · Thu Feb 02 04:00:00 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: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• 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: AC02-05CH11231
• OSTI ID: 901674
• Report Number(s): LBNL--59476; BnR: KB0401024
• Journal Information: Physical Review C, Journal Name: Physical Review C Vol. 74
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALIGNMENT
BRANCHING RATIO
CHAINS
ENERGY LEVELS
EXCITATION
Fission Gamma Spectroscopy Triaxial Rotational Bands
NEUTRONS
NUCLEI
SHAPE
SPONTANEOUS FISSION