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Title: Nuclear Data Sheets for A = 129

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 γ 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 {sup 129}Pm and {sup 129}Sm, and for {sup 129}Ag and {sup 129}Cd, only limited information is available for the g.s. and isomers. The decay schemes of {sup 129}Ag, {sup 129}Pm and {sup 129}Sm are unknown, and those for {sup 129}Cd, {sup 129}In, {sup 129}Ce, {sup 129}Pr and {sup 129}Nd are incomplete. Many γ rays and extended level schemes have been reported for the ground state and isomer decays of {sup 129}Ba to {sup 129}Cs, 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 {sup 129}Ba with nearly the same half-lives. Isomerism ismore » expected in {sup 129}Pr, but there is no confirmed identification. Low-lying level structure in {sup 129}Nd, including identification of a possible third long-lived isomer in this nuclide, remains uncertain. The spin-parity assignments of (5/2+) for the ground state and (7/2−) for an isomer at 107.6 keV in {sup 129}Ce 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 {sup 129}Ce are needed to settle this issue. Confirmed spins and parities of the ground state and isomer of {sup 129}La are also lacking. Assignments in this work are mainly based on systematics of h{sub 11/2} decoupled structures. A direct measurement of ground state spin of {sup 129}La will also be desirable. Recommended data presented in this work supersede those in previous NDS evaluations of A=129 nuclides published by 1996Te01, 1983Ha46 and 1972Ho55.« less
Authors:
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Publication Date:
OSTI Identifier:
22443553
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nuclear Data Sheets; Journal Volume: 121; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BARIUM 129; CADMIUM 129; CERIUM 129; CESIUM 129; EVALUATED DATA; EXCITED STATES; GAMMA RADIATION; GROUND STATES; HALF-LIFE; HYPERFINE STRUCTURE; INDIUM 129; ISOMERS; LANTHANUM 129; NEODYMIUM 129; NUCLEAR DATA COLLECTIONS; NUCLEAR DECAY; PARITY; PRASEODYMIUM 129; PROMETHIUM 129; SAMARIUM 129; SILVER 129; SPIN