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Title: γ -soft Ba 146 and the role of nonaxial shapes at N 90

Abstract

Low-spin states in the neutron-rich, N = 90 nuclide 146Ba were populated following β decay of 146Cs , with the goal of clarifying the development of deformation in barium isotopes through delineation of their nonyrast structures. Fission fragments of 146Cs were extracted from a 1.7-Ci 252Cf source and mass selected using the CAlifornium Rare Ion Breeder Upgrade (CARIBU) facility. Low-energy ions were deposited at the center of a box of thin β detectors, surrounded by a highly efficient high-purity Ge array. The new 146Ba decay scheme now contains 31 excited levels extending up to ~2.5 MeV excitation energy, double what was previously known. These data are compared to predictions from the interacting boson approximation (IBA) model. It appears that the abrupt shape change found at N = 90 in Sm and Gd is much more gradual in Ba and Ce, due to an enhanced role of the γ degree of freedom.

Authors:
 [1];  [1];  [2];  [3];  [3];  [3];  [3];  [4];  [1];  [3];  [1];  [3];  [1];  [3];  [1];  [5];  [6];  [7];  [1];  [3] more »;  [8];  [9];  [10];  [11];  [3];  [3];  [6];  [2];  [5];  [7];  [10];  [3] « less
  1. Univ. of Massachusetts, Lowell, MA (United States). Dept. of Physics and Applied Physics
  2. Brookhaven National Lab. (BNL), Upton, NY (United States). National Nuclear Data Center
  3. Argonne National Lab. (ANL), Argonne, IL (United States). Physics Division
  4. Argonne National Lab. (ANL), Argonne, IL (United States). Physics Division; Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry
  5. Florida State Univ., Tallahassee, FL (United States). Dept. of Physics
  6. Univ. of Massachusetts, Lowell, MA (United States). Dept. of Physics and Applied Physics; Univ. of Surrey, Guildford (United Kingdom). Dept. of Physics
  7. Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry
  8. Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division
  9. Univ. of Kentucky, Lexington, KY (United States). Dept. of Chemistry; Univ. of Kentucky, Lexington, KY (United States). Dept. of Physics and Astronomy
  10. Vanderbilt Univ., Nashville, TN (United States). Dept. of Physics
  11. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26); National Science Foundation (NSF)
OSTI Identifier:
1430665
Alternate Identifier(s):
OSTI ID: 1234769
Grant/Contract Number:  
AC02-05CH11231; FG02-94ER40848; FG02-94ER40834; AC02-06CH1135; 1064819; AC02-06CH11357
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 93; Journal Issue: 1; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Mitchell, A. J., Lister, C. J., McCutchan, E. A., Albers, M., Ayangeakaa, A. D., Bertone, P. F., Carpenter, M. P., Chiara, C. J., Chowdhury, P., Clark, J. A., Copp, P., David, H. M., Deo, A. Y., DiGiovine, B., D'Olympia, N., Dungan, R., Harding, R. D., Harker, J., Hota, S. S., Janssens, R. V. F., Kondev, F. G., Liu, S. H., Ramayya, A. V., Rissanen, J., Savard, G., Seweryniak, D., Shearman, R., Sonzogni, A. A., Tabor, S. L., Walters, W. B., Wang, E., and Zhu, S. γ -soft Ba146 and the role of nonaxial shapes at N≈90. United States: N. p., 2016. Web. doi:10.1103/PhysRevC.93.014306.
Mitchell, A. J., Lister, C. J., McCutchan, E. A., Albers, M., Ayangeakaa, A. D., Bertone, P. F., Carpenter, M. P., Chiara, C. J., Chowdhury, P., Clark, J. A., Copp, P., David, H. M., Deo, A. Y., DiGiovine, B., D'Olympia, N., Dungan, R., Harding, R. D., Harker, J., Hota, S. S., Janssens, R. V. F., Kondev, F. G., Liu, S. H., Ramayya, A. V., Rissanen, J., Savard, G., Seweryniak, D., Shearman, R., Sonzogni, A. A., Tabor, S. L., Walters, W. B., Wang, E., & Zhu, S. γ -soft Ba146 and the role of nonaxial shapes at N≈90. United States. doi:10.1103/PhysRevC.93.014306.
Mitchell, A. J., Lister, C. J., McCutchan, E. A., Albers, M., Ayangeakaa, A. D., Bertone, P. F., Carpenter, M. P., Chiara, C. J., Chowdhury, P., Clark, J. A., Copp, P., David, H. M., Deo, A. Y., DiGiovine, B., D'Olympia, N., Dungan, R., Harding, R. D., Harker, J., Hota, S. S., Janssens, R. V. F., Kondev, F. G., Liu, S. H., Ramayya, A. V., Rissanen, J., Savard, G., Seweryniak, D., Shearman, R., Sonzogni, A. A., Tabor, S. L., Walters, W. B., Wang, E., and Zhu, S. Tue . "γ -soft Ba146 and the role of nonaxial shapes at N≈90". United States. doi:10.1103/PhysRevC.93.014306. https://www.osti.gov/servlets/purl/1430665.
@article{osti_1430665,
title = {γ -soft Ba146 and the role of nonaxial shapes at N≈90},
author = {Mitchell, A. J. and Lister, C. J. and McCutchan, E. A. and Albers, M. and Ayangeakaa, A. D. and Bertone, P. F. and Carpenter, M. P. and Chiara, C. J. and Chowdhury, P. and Clark, J. A. and Copp, P. and David, H. M. and Deo, A. Y. and DiGiovine, B. and D'Olympia, N. and Dungan, R. and Harding, R. D. and Harker, J. and Hota, S. S. and Janssens, R. V. F. and Kondev, F. G. and Liu, S. H. and Ramayya, A. V. and Rissanen, J. and Savard, G. and Seweryniak, D. and Shearman, R. and Sonzogni, A. A. and Tabor, S. L. and Walters, W. B. and Wang, E. and Zhu, S.},
abstractNote = {Low-spin states in the neutron-rich, N = 90 nuclide 146Ba were populated following β decay of 146Cs , with the goal of clarifying the development of deformation in barium isotopes through delineation of their nonyrast structures. Fission fragments of 146Cs were extracted from a 1.7-Ci 252Cf source and mass selected using the CAlifornium Rare Ion Breeder Upgrade (CARIBU) facility. Low-energy ions were deposited at the center of a box of thin β detectors, surrounded by a highly efficient high-purity Ge array. The new 146Ba decay scheme now contains 31 excited levels extending up to ~2.5 MeV excitation energy, double what was previously known. These data are compared to predictions from the interacting boson approximation (IBA) model. It appears that the abrupt shape change found at N = 90 in Sm and Gd is much more gradual in Ba and Ce, due to an enhanced role of the γ degree of freedom.},
doi = {10.1103/PhysRevC.93.014306},
journal = {Physical Review C},
number = 1,
volume = 93,
place = {United States},
year = {2016},
month = {1}
}

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