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摘要
The experimental nuclear spectroscopic data for known nuclides of mass number 129 (Ag, Cd, In, Sn, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm) have been evaluated and presented together with adopted properties for levels and gamma rays. This evaluation represents a revision of the previous one 18 years ago by Y. Tendow (1996Te01). Extensive new data have become available for many nuclides in the intervening years, although, no data are available for excited states in Pm-129 and Sm-129, and for Ag-129 and Cd-129, only limited information is available for the g.s. and isomers. The decay schemes of Ag-129, Pm-129 and Sm-129 are unknown, and those for Cd-129, In-129, Ce-129, Pr-129 and Nd-129 are incomplete. Many gamma rays and extended level schemes have been reported for the ground state and isomer decays of Ba-129 to Cs-129, yet the adopted set of intensities in this evaluation originate from a brief paper in an annual laboratory report. There remain several unplaced gamma rays, coupled with ambiguity about division of intensities amongst the two activities of Ba-129 with nearly the same half-lives. Isomerism is expected in Pr-129, but there is no confirmed identification. Low-lying level structure in Nd-129, including identification of a possible third long-lived isomer in this nuclide, remains uncertain. %26lt;br%26gt;The spin-parity assignments of (5/2+) for the ground state and (7/2-) for an isomer at 107.6 keV in Ce-129 are assigned based on strong support from systematics and band configurations, yet this result is in contradiction with the quadrupole interaction hyperfine structure measurement which favors 9/2- over 7/2- for the isomer, consequently 7/2+ for the ground state. Direct measurements of spins of ground state and isomer of Ce-129 are needed to settle this issue. Confirmed spins and parities of the ground state and isomer of La-129 are also lacking. Assignments in this work are mainly based on systematics of h(11/2) decoupled structures. A direct measurement of ground state spin of La-129 will also be desirable. %26lt;br%26gt;Recommended data presented in this work supersede those in previous NDS evaluations of A=129 nuclides published by 1996Te01, 1983Ha46 and 1972Ho55.
- 出版日期2014-10
