1
|
Cox I, Xu ZY, Grzywacz R, Ong WJ, Rasco BC, Kitamura N, Hoskins D, Neupane S, Ruland TJ, Allmond JM, King TT, Lubna RS, Rykaczewski KP, Schatz H, Sherrill BM, Tarasov OB, Ayangeakaa AD, Berg HC, Bleuel DL, Cerizza G, Christie J, Chester A, Davis J, Dembski C, Doetsch AA, Duarte JG, Estrade A, Fijałkowska A, Gray TJ, Good EC, Haak K, Hanai S, Harke JT, Harris C, Hermansen K, Hoff DEM, Jain R, Karny M, Kolos K, Laminack A, Liddick SN, Longfellow B, Lyons S, Madurga M, Mogannam MJ, Nowicki A, Ogunbeku TH, Owens-Fryar G, Rajabali MM, Richard AL, Ronning EK, Rose GE, Siegl K, Singh M, Spyrou A, Sweet A, Tsantiri A, Walters WB, Yokoyama R. Proton Shell Gaps in N=28 Nuclei from the First Complete Spectroscopy Study with FRIB Decay Station Initiator. Phys Rev Lett 2024; 132:152503. [PMID: 38682970 DOI: 10.1103/physrevlett.132.152503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/12/2023] [Accepted: 03/08/2024] [Indexed: 05/01/2024]
Abstract
The first complete measurement of the β-decay strength distribution of _{17}^{45}Cl_{28} was performed at the Facility for Rare Isotope Beams (FRIB) with the FRIB Decay Station Initiator during the second FRIB experiment. The measurement involved the detection of neutrons and γ rays in two focal planes of the FRIB Decay Station Initiator in a single experiment for the first time. This enabled an analytical consistency in extracting the β-decay strength distribution over the large range of excitation energies, including neutron unbound states. We observe a rapid increase in the β-decay strength distribution above the neutron separation energy in _{18}^{45}Ar_{27}. This was interpreted to be caused by the transitioning of neutrons into protons excited across the Z=20 shell gap. The SDPF-MU interaction with reduced shell gap best reproduced the data. The measurement demonstrates a new approach that is sensitive to the proton shell gap in neutron rich nuclei according to SDPF-MU calculations.
Collapse
Affiliation(s)
- I Cox
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Z Y Xu
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - R Grzywacz
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - W-J Ong
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - B C Rasco
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - N Kitamura
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - D Hoskins
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - S Neupane
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - T J Ruland
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - J M Allmond
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T T King
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R S Lubna
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - K P Rykaczewski
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H Schatz
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - B M Sherrill
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - O B Tarasov
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - A D Ayangeakaa
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Triangle Universities Nuclear Laboratory, Duke University, Durham, North Carolina 27708, USA
| | - H C Berg
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D L Bleuel
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G Cerizza
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Christie
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - A Chester
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Davis
- Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - C Dembski
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - A A Doetsch
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J G Duarte
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A Estrade
- Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - A Fijałkowska
- Faculty of Physics, University of Warsaw, PL 02-093 Warsaw, Poland
| | - T J Gray
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E C Good
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - K Haak
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - S Hanai
- Center for Nuclear Study, University of Tokyo, Wako, Saitama 351-0198, Japan
| | - J T Harke
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C Harris
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - K Hermansen
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D E M Hoff
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R Jain
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Karny
- Faculty of Physics, University of Warsaw, PL 02-093 Warsaw, Poland
| | - K Kolos
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A Laminack
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S N Liddick
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - B Longfellow
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S Lyons
- Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - M Madurga
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - M J Mogannam
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Nowicki
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - T H Ogunbeku
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G Owens-Fryar
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - M M Rajabali
- Physics Department, Tennessee Technological University, Cookeville, Tennessee 38505, USA
| | - A L Richard
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E K Ronning
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - G E Rose
- University of California, Berkeley, Berkeley, California 94704, USA
| | - K Siegl
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - M Singh
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Spyrou
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Sweet
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A Tsantiri
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - W B Walters
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - R Yokoyama
- Center for Nuclear Study, University of Tokyo, Wako, Saitama 351-0198, Japan
| |
Collapse
|
2
|
Gray TJ, Allmond JM, Xu Z, King TT, Lubna RS, Crawford HL, Tripathi V, Crider BP, Grzywacz R, Liddick SN, Macchiavelli AO, Miyagi T, Poves A, Andalib A, Argo E, Benetti C, Bhattacharya S, Campbell CM, Carpenter MP, Chan J, Chester A, Christie J, Clark BR, Cox I, Doetsch AA, Dopfer J, Duarte JG, Fallon P, Frotscher A, Gaballah T, Harke JT, Heideman J, Huegen H, Holt JD, Jain R, Kitamura N, Kolos K, Kondev FG, Laminack A, Longfellow B, Luitel S, Madurga M, Mahajan R, Mogannam MJ, Morse C, Neupane S, Nowicki A, Ogunbeku TH, Ong WJ, Porzio C, Prokop CJ, Rasco BC, Ronning EK, Rubino E, Ruland TJ, Rykaczewski KP, Schaedig L, Seweryniak D, Siegl K, Singh M, Stuchbery AE, Tabor SL, Tang TL, Wheeler T, Winger JA, Wood JL. Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB. Phys Rev Lett 2023; 130:242501. [PMID: 37390416 DOI: 10.1103/physrevlett.130.242501] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/26/2023] [Indexed: 07/02/2023]
Abstract
Excited-state spectroscopy from the first experiment at the Facility for Rare Isotope Beams (FRIB) is reported. A 24(2)-μs isomer was observed with the FRIB Decay Station initiator (FDSi) through a cascade of 224- and 401-keV γ rays in coincidence with ^{32}Na nuclei. This is the only known microsecond isomer (1 μs≤T_{1/2}<1 ms) in the region. This nucleus is at the heart of the N=20 island of shape inversion and is at the crossroads of the spherical shell-model, deformed shell-model, and ab initio theories. It can be represented as the coupling of a proton hole and neutron particle to ^{32}Mg, ^{32}Mg+π^{-1}+ν^{+1}. This odd-odd coupling and isomer formation provides a sensitive measure of the underlying shape degrees of freedom of ^{32}Mg, where the onset of spherical-to-deformed shape inversion begins with a low-lying deformed 2^{+} state at 885 keV and a low-lying shape-coexisting 0_{2}^{+} state at 1058 keV. We suggest two possible explanations for the 625-keV isomer in ^{32}Na: a 6^{-} spherical shape isomer that decays by E2 or a 0^{+} deformed spin isomer that decays by M2. The present results and calculations are most consistent with the latter, indicating that the low-lying states are dominated by deformation.
Collapse
Affiliation(s)
- T J Gray
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J M Allmond
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Z Xu
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - T T King
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R S Lubna
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - V Tripathi
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - B P Crider
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - R Grzywacz
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - S N Liddick
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - A O Macchiavelli
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T Miyagi
- Department of Physics, Technische Universität Darmstadt, Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - A Poves
- Departamento de Fìsica Teórica and IFT-UAM/CSIC, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - A Andalib
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Argo
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Benetti
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - S Bhattacharya
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - C M Campbell
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M P Carpenter
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Chan
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A Chester
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Christie
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - B R Clark
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - I Cox
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A A Doetsch
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Dopfer
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J G Duarte
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Fallon
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A Frotscher
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - T Gaballah
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - J T Harke
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J Heideman
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - H Huegen
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - J D Holt
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, McGill University, Montréal, Quebec City H3A 2T8, Canada
| | - R Jain
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - N Kitamura
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - K Kolos
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - F G Kondev
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Laminack
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - B Longfellow
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S Luitel
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - M Madurga
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - R Mahajan
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - M J Mogannam
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Morse
- National Nuclear Data Center, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - S Neupane
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A Nowicki
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - T H Ogunbeku
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - W-J Ong
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C Porzio
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C J Prokop
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B C Rasco
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E K Ronning
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Rubino
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - T J Ruland
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - K P Rykaczewski
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L Schaedig
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Seweryniak
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - K Siegl
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - M Singh
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A E Stuchbery
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - S L Tabor
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T L Tang
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T Wheeler
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J A Winger
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - J L Wood
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA
| |
Collapse
|
3
|
Lewis R, Couture A, Liddick SN, Spyrou A, Bleuel DL, Campo LC, Crider BP, Dombos AC, Guttormsen M, Kawano T, Larsen AC, Lewis AM, Mosby S, Perdikakis G, Prokop CJ, Quinn SJ, Renstrøm T, Siem S. Statistical (n, γ ) cross section model comparison for short-lived nuclei. Eur Phys J A Hadron Nucl 2023; 59:42. [PMID: 36915898 PMCID: PMC9998597 DOI: 10.1140/epja/s10050-023-00920-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 01/11/2023] [Indexed: 06/18/2023]
Abstract
UNLABELLED Neutron-capture cross sections of neutron-rich nuclei are calculated using a Hauser-Feshbach model when direct experimental cross sections cannot be obtained. A number of codes to perform these calculations exist, and each makes different assumptions about the underlying nuclear physics. We investigated the systematic uncertainty associated with the choice of Hauser-Feshbach code used to calculate the neutron-capture cross section of a short-lived nucleus. The neutron-capture cross section for 73 Zn (n, γ ) 74 Zn was calculated using three Hauser-Feshbach statistical model codes: TALYS, CoH, and EMPIRE. The calculation was first performed without any changes to the default settings in each code. Then an experimentally obtained nuclear level density (NLD) and γ -ray strength function ( γ SF ) were included. Finally, the nuclear structure information was made consistent across the codes. The neutron-capture cross sections obtained from the three codes are in good agreement after including the experimentally obtained NLD and γ SF , accounting for differences in the underlying nuclear reaction models, and enforcing consistent approximations for unknown nuclear data. It is possible to use consistent inputs and nuclear physics to reduce the differences in the calculated neutron-capture cross section from different Hauser-Feshbach codes. However, ensuring the treatment of the input of experimental data and other nuclear physics are similar across multiple codes requires a careful investigation. For this reason, more complete documentation of the inputs and physics chosen is important. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1140/epja/s10050-023-00920-0.
Collapse
Affiliation(s)
- R. Lewis
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Department of Chemistry, Michigan State University, East Lansing, MI 48824 USA
- Present Address: Zeno Power Systems, Inc., Washington, DC USA
| | - A. Couture
- Los Alamos National Laboratory, Los Alamos, NM 87545 USA
| | - S. N. Liddick
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Department of Chemistry, Michigan State University, East Lansing, MI 48824 USA
| | - A. Spyrou
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 USA
| | - D. L. Bleuel
- Lawrence Livermore National Laboratory, Livermore, CA 94550 USA
| | - L. Crespo Campo
- Department of Physics, University of Oslo, 0316 Oslo, Norway
| | - B. P. Crider
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 USA
| | - A. C. Dombos
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 USA
| | - M. Guttormsen
- Department of Physics, University of Oslo, 0316 Oslo, Norway
| | - T. Kawano
- Los Alamos National Laboratory, Los Alamos, NM 87545 USA
| | - A. C. Larsen
- Department of Physics, University of Oslo, 0316 Oslo, Norway
| | - A. M. Lewis
- Department of Nuclear Engineering, University of California Berkeley, Berkeley, CA 94720 USA
- Present Address: Naval Nuclear Laboratory, New York, USA
| | - S. Mosby
- Los Alamos National Laboratory, Los Alamos, NM 87545 USA
| | - G. Perdikakis
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 USA
- Central Michigan University, Mount Pleasant, MI 48859 USA
| | - C. J. Prokop
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Department of Chemistry, Michigan State University, East Lansing, MI 48824 USA
| | - S. J. Quinn
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 USA
| | - T. Renstrøm
- Department of Physics, University of Oslo, 0316 Oslo, Norway
| | - S. Siem
- Department of Physics, University of Oslo, 0316 Oslo, Norway
| |
Collapse
|
4
|
Crawford HL, Tripathi V, Allmond JM, Crider BP, Grzywacz R, Liddick SN, Andalib A, Argo E, Benetti C, Bhattacharya S, Campbell CM, Carpenter MP, Chan J, Chester A, Christie J, Clark BR, Cox I, Doetsch AA, Dopfer J, Duarte JG, Fallon P, Frotscher A, Gaballah T, Gray TJ, Harke JT, Heideman J, Heugen H, Jain R, King TT, Kitamura N, Kolos K, Kondev FG, Laminack A, Longfellow B, Lubna RS, Luitel S, Madurga M, Mahajan R, Mogannam MJ, Morse C, Neupane S, Nowicki A, Ogunbeku TH, Ong WJ, Porzio C, Prokop CJ, Rasco BC, Ronning EK, Rubino E, Ruland TJ, Rykaczewski KP, Schaedig L, Seweryniak D, Siegl K, Singh M, Tabor SL, Tang TL, Wheeler T, Winger JA, Xu Z. Crossing N=28 Toward the Neutron Drip Line: First Measurement of Half-Lives at FRIB. Phys Rev Lett 2022; 129:212501. [PMID: 36461950 DOI: 10.1103/physrevlett.129.212501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/14/2022] [Indexed: 06/17/2023]
Abstract
New half-lives for exotic isotopes approaching the neutron drip-line in the vicinity of N∼28 for Z=12-15 were measured at the Facility for Rare Isotope Beams (FRIB) with the FRIB decay station initiator. The first experimental results are compared to the latest quasiparticle random phase approximation and shell-model calculations. Overall, the measured half-lives are consistent with the available theoretical descriptions and suggest a well-developed region of deformation below ^{48}Ca in the N=28 isotones. The erosion of the Z=14 subshell closure in Si is experimentally confirmed at N=28, and a reduction in the ^{38}Mg half-life is observed as compared with its isotopic neighbors, which does not seem to be predicted well based on the decay energy and deformation trends. This highlights the need for both additional data in this very exotic region, and for more advanced theoretical efforts.
Collapse
Affiliation(s)
- H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - V Tripathi
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - J M Allmond
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - B P Crider
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - R Grzywacz
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - S N Liddick
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Andalib
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Argo
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Benetti
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - S Bhattacharya
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - C M Campbell
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M P Carpenter
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Chan
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A Chester
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Christie
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - B R Clark
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - I Cox
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A A Doetsch
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Dopfer
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J G Duarte
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Fallon
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A Frotscher
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - T Gaballah
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - T J Gray
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J T Harke
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J Heideman
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - H Heugen
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - R Jain
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - T T King
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - N Kitamura
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - K Kolos
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - F G Kondev
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Laminack
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - B Longfellow
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R S Lubna
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - S Luitel
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - M Madurga
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - R Mahajan
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - M J Mogannam
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Morse
- Brookhaven National Laboratory, Upton, New York 11973, USA
| | - S Neupane
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A Nowicki
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - T H Ogunbeku
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - W-J Ong
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C Porzio
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C J Prokop
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B C Rasco
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E K Ronning
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Rubino
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - T J Ruland
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - K P Rykaczewski
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L Schaedig
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Seweryniak
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - K Siegl
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - M Singh
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - S L Tabor
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T L Tang
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T Wheeler
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J A Winger
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - Z Xu
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| |
Collapse
|
5
|
Ong WJ, Brown EF, Browne J, Ahn S, Childers K, Crider BP, Dombos AC, Gupta SS, Hitt GW, Langer C, Lewis R, Liddick SN, Lyons S, Meisel Z, Möller P, Montes F, Naqvi F, Pereira J, Prokop C, Richman D, Schatz H, Schmidt K, Spyrou A. β Decay of ^{61}V and its Role in Cooling Accreted Neutron Star Crusts. Phys Rev Lett 2020; 125:262701. [PMID: 33449748 DOI: 10.1103/physrevlett.125.262701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
The interpretation of observations of cooling neutron star crusts in quasipersistent x-ray transients is affected by predictions of the strength of neutrino cooling via crust Urca processes. The strength of crust Urca neutrino cooling depends sensitively on the electron-capture and β-decay ground-state-to-ground-state transition strengths of neutron-rich rare isotopes. Nuclei with a mass number of A=61 are predicted to be among the most abundant in accreted crusts, and the last remaining experimentally undetermined ground-state-to-ground-state transition strength was the β decay of ^{61}V. This Letter reports the first experimental determination of this transition strength, a ground-state branching of 8.1_{-3.1}^{+4.0}%, corresponding to a log ft value of 5.5_{-0.2}^{+0.2}. This result was achieved through the measurement of the β-delayed γ rays using the total absorption spectrometer SuN and the measurement of the β-delayed neutron branch using the neutron long counter system NERO at the National Superconducting Cyclotron Laboratory at Michigan State University. This method helps to mitigate the impact of the pandemonium effect in extremely neutron-rich nuclei on experimental results. The result implies that A=61 nuclei do not provide the strongest cooling in accreted neutron star crusts as expected by some predictions, but that their cooling is still larger compared to most other mass numbers. Only nuclei with mass numbers 31, 33, and 55 are predicted to be cooling more strongly. However, the theoretical predictions for the transition strengths of these nuclei are not consistently accurate enough to draw conclusions on crust cooling. With the experimental approach developed in this work, all relevant transitions are within reach to be studied in the future.
Collapse
Affiliation(s)
- W-J Ong
- Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
| | - E F Brown
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Computational Mathematics, Science, and Engineering, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Browne
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
| | - S Ahn
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
- Cylotron Institute, Texas A&M University, College Station, Texas 77843, USA
| | - K Childers
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - B P Crider
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - A C Dombos
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
| | - S S Gupta
- Indian Institute of Technology Ropar, Nangal Road, Rupnagar (Ropar), Punjab 140 001, India
| | - G W Hitt
- Department of Physics and Engineering Science, Coastal Carolina University, Conway, South Carolina 29528, USA
| | - C Langer
- Institute for Applied Physics, Goethe-University Frankfurt a. M., Frankfurt am Main 60438, Germany
| | - R Lewis
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - S N Liddick
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - S Lyons
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
| | - Z Meisel
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Ohio Univeristy, Athens, Ohio 45701, USA
| | - P Möller
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - F Montes
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
| | - F Naqvi
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics & Astrophysics, University of Delhi, Delhi 110007, India
| | - J Pereira
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Prokop
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D Richman
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - H Schatz
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
| | - K Schmidt
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Spyrou
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics-Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
| |
Collapse
|
6
|
Kolos K, Miller D, Grzywacz R, Iwasaki H, Al-Shudifat M, Bazin D, Bingham CR, Braunroth T, Cerizza G, Gade A, Lemasson A, Liddick SN, Madurga M, Morse C, Portillo M, Rajabali MM, Recchia F, Riedinger LL, Voss P, Walters WB, Weisshaar D, Whitmore K, Wimmer K, Tostevin JA. Publisher's Note: Direct Lifetime Measurements of the Excited States in ^{72}Ni [Phys. Rev. Lett. 116, 122502 (2016)]. Phys Rev Lett 2020; 124:209901. [PMID: 32501080 DOI: 10.1103/physrevlett.124.209901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Indexed: 06/11/2023]
Abstract
This corrects the article DOI: 10.1103/PhysRevLett.116.122502.
Collapse
|
7
|
Hoff DEM, Rogers AM, Wang SM, Bender PC, Brandenburg K, Childers K, Clark JA, Dombos AC, Doucet ER, Jin S, Lewis R, Liddick SN, Lister CJ, Meisel Z, Morse C, Nazarewicz W, Schatz H, Schmidt K, Soltesz D, Subedi SK, Waniganeththi S. Mirror-symmetry violation in bound nuclear ground states. Nature 2020; 580:52-55. [PMID: 32238942 DOI: 10.1038/s41586-020-2123-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 01/22/2020] [Indexed: 11/09/2022]
Abstract
Conservation laws are deeply related to any symmetry present in a physical system1,2. Analogously to electrons in atoms exhibiting spin symmetries3, it is possible to consider neutrons and protons in the atomic nucleus as projections of a single fermion with an isobaric spin (isospin) of t = 1/2 (ref. 4). Every nuclear state is thus characterized by a total isobaric spin T and a projection Tz-two quantities that are largely conserved in nuclear reactions and decays5,6. A mirror symmetry emerges from this isobaric-spin formalism: nuclei with exchanged numbers of neutrons and protons, known as mirror nuclei, should have an identical set of states7, including their ground state, labelled by their total angular momentum J and parity π. Here we report evidence of mirror-symmetry violation in bound nuclear ground states within the mirror partners strontium-73 and bromine-73. We find that a J π = 5/2- spin assignment is needed to explain the proton-emission pattern observed from the T = 3/2 isobaric-analogue state in rubidium-73, which is identical to the ground state of strontium-73. Therefore the ground state of strontium-73 must differ from its J π = 1/2- mirror bromine-73. This observation offers insights into charge-symmetry-breaking forces acting in atomic nuclei.
Collapse
Affiliation(s)
- D E M Hoff
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA, USA.
| | - A M Rogers
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA, USA.
| | - S M Wang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA
| | - P C Bender
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA, USA
| | - K Brandenburg
- Department of Physics and Astronomy, Ohio University, Athens, OH, USA
| | - K Childers
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA.,Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - J A Clark
- Physics Division, Argonne National Laboratory, Argonne, IL, USA
| | - A C Dombos
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA.,Department of Physics and Astronomy, Michigan State University, East Lansing, MI, USA.,JINA-CEE, Michigan State University, East Lansing, MI, USA
| | - E R Doucet
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA, USA
| | - S Jin
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA.,JINA-CEE, Michigan State University, East Lansing, MI, USA
| | - R Lewis
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA.,Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - S N Liddick
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA.,Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - C J Lister
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA, USA
| | - Z Meisel
- Department of Physics and Astronomy, Ohio University, Athens, OH, USA
| | - C Morse
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA, USA.,Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - W Nazarewicz
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI, USA.,FRIB Laboratory, Michigan State University, East Lansing, MI, USA
| | - H Schatz
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA.,Department of Physics and Astronomy, Michigan State University, East Lansing, MI, USA.,JINA-CEE, Michigan State University, East Lansing, MI, USA
| | - K Schmidt
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, USA.,JINA-CEE, Michigan State University, East Lansing, MI, USA.,Institute of Nuclear and Particle Physics, TU Dresden, Dresden, Germany
| | - D Soltesz
- Department of Physics and Astronomy, Ohio University, Athens, OH, USA
| | - S K Subedi
- Department of Physics and Astronomy, Ohio University, Athens, OH, USA
| | - S Waniganeththi
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA, USA
| |
Collapse
|
8
|
Liddick SN, Spyrou A, Crider BP, Naqvi F, Larsen AC, Guttormsen M, Mumpower M, Surman R, Perdikakis G, Bleuel DL, Couture A, Crespo Campo L, Dombos AC, Lewis R, Mosby S, Nikas S, Prokop CJ, Renstrom T, Rubio B, Siem S, Quinn SJ. Publisher's Note: Experimental Neutron Capture Rate Constraint Far from Stability [Phys. Rev. Lett. 116, 242502 (2016)]. Phys Rev Lett 2019; 122:129902. [PMID: 30978071 DOI: 10.1103/physrevlett.122.129902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Indexed: 06/09/2023]
Abstract
This corrects the article DOI: 10.1103/PhysRevLett.116.242502.
Collapse
|
9
|
Spyrou A, Liddick SN, Naqvi F, Crider BP, Dombos AC, Bleuel DL, Brown BA, Couture A, Crespo Campo L, Guttormsen M, Larsen AC, Lewis R, Möller P, Mosby S, Mumpower MR, Perdikakis G, Prokop CJ, Renstrøm T, Siem S, Quinn SJ, Valenta S. Strong Neutron-γ Competition above the Neutron Threshold in the Decay of ^{70}Co. Phys Rev Lett 2016; 117:142701. [PMID: 27740831 DOI: 10.1103/physrevlett.117.142701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Indexed: 06/06/2023]
Abstract
The β-decay intensity of ^{70}Co was measured for the first time using the technique of total absorption spectroscopy. The large β-decay Q value [12.3(3) MeV] offers a rare opportunity to study β-decay properties in a broad energy range. Two surprising features were observed in the experimental results, namely, the large fragmentation of the β intensity at high energies, as well as the strong competition between γ rays and neutrons, up to more than 2 MeV above the neutron-separation energy. The data are compared to two theoretical calculations: the shell model and the quasiparticle random phase approximation (QRPA). Both models seem to be missing a significant strength at high excitation energies. Possible interpretations of this discrepancy are discussed. The shell model is used for a detailed nuclear structure interpretation and helps to explain the observed γ-neutron competition. The comparison to the QRPA calculations is done as a means to test a model that provides global β-decay properties for astrophysical calculations. Our work demonstrates the importance of performing detailed comparisons to experimental results, beyond the simple half-life comparisons. A realistic and robust description of the β-decay intensity is crucial for our understanding of nuclear structure as well as of r-process nucleosynthesis.
Collapse
Affiliation(s)
- A Spyrou
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - S N Liddick
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - F Naqvi
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - B P Crider
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - A C Dombos
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - D L Bleuel
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550-9234, USA
| | - B A Brown
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Couture
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - L Crespo Campo
- Department of Physics, University of Oslo, NO-0316 Oslo, Norway
| | - M Guttormsen
- Department of Physics, University of Oslo, NO-0316 Oslo, Norway
| | - A C Larsen
- Department of Physics, University of Oslo, NO-0316 Oslo, Norway
| | - R Lewis
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - P Möller
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S Mosby
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - M R Mumpower
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - G Perdikakis
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
- Central Michigan University, Mt. Pleasant, Michigan 48859, USA
| | - C J Prokop
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - T Renstrøm
- Department of Physics, University of Oslo, NO-0316 Oslo, Norway
| | - S Siem
- Department of Physics, University of Oslo, NO-0316 Oslo, Norway
| | - S J Quinn
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - S Valenta
- Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, CZ-180 00 Prague 8, Czech Republic
| |
Collapse
|
10
|
Liddick SN, Spyrou A, Crider BP, Naqvi F, Larsen AC, Guttormsen M, Mumpower M, Surman R, Perdikakis G, Bleuel DL, Couture A, Crespo Campo L, Dombos AC, Lewis R, Mosby S, Nikas S, Prokop CJ, Renstrom T, Rubio B, Siem S, Quinn SJ. Experimental Neutron Capture Rate Constraint Far from Stability. Phys Rev Lett 2016; 116:242502. [PMID: 27367386 DOI: 10.1103/physrevlett.116.242502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Indexed: 06/06/2023]
Abstract
Nuclear reactions where an exotic nucleus captures a neutron are critical for a wide variety of applications, from energy production and national security, to astrophysical processes, and nucleosynthesis. Neutron capture rates are well constrained near stable isotopes where experimental data are available; however, moving far from the valley of stability, uncertainties grow by orders of magnitude. This is due to the complete lack of experimental constraints, as the direct measurement of a neutron-capture reaction on a short-lived nucleus is extremely challenging. Here, we report on the first experimental extraction of a neutron capture reaction rate on ^{69}Ni, a nucleus that is five neutrons away from the last stable isotope of Ni. The implications of this measurement on nucleosynthesis around mass 70 are discussed, and the impact of similar future measurements on the understanding of the origin of the heavy elements in the cosmos is presented.
Collapse
Affiliation(s)
- S N Liddick
- National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Spyrou
- National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - B P Crider
- National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824, USA
| | - F Naqvi
- National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824, USA
| | - A C Larsen
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - M Guttormsen
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - M Mumpower
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
| | - R Surman
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - G Perdikakis
- National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
- Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - D L Bleuel
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550-9234, USA
| | - A Couture
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - L Crespo Campo
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - A C Dombos
- National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - R Lewis
- National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - S Mosby
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S Nikas
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
- Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - C J Prokop
- National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - T Renstrom
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - B Rubio
- IFIC, CSIC-Universidad de Valencia, 46071 Valencia, Spain
| | - S Siem
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - S J Quinn
- National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| |
Collapse
|
11
|
Kolos K, Miller D, Grzywacz R, Iwasaki H, Al-Shudifat M, Bazin D, Bingham CR, Braunroth T, Cerizza G, Gade A, Lemasson A, Liddick SN, Madurga M, Morse C, Portillo M, Rajabali MM, Recchia F, Riedinger LL, Voss P, Walters WB, Weisshaar D, Whitmore K, Wimmer K, Tostevin JA. Direct Lifetime Measurements of the Excited States in (72)Ni. Phys Rev Lett 2016; 116:122502. [PMID: 27058074 DOI: 10.1103/physrevlett.116.122502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Indexed: 06/05/2023]
Abstract
The lifetimes of the first excited 2^{+} and 4^{+} states in ^{72}Ni were measured at the National Superconducting Cyclotron Laboratory with the recoil-distance Doppler-shift method, a model-independent probe to obtain the reduced transition probability. Excited states in ^{72}Ni were populated by the one-proton knockout reaction of an intermediate energy ^{73}Cu beam. γ-ray-recoil coincidences were detected with the γ-ray tracking array GRETINA and the S800 spectrograph. Our results provide evidence of enhanced transition probability B(E2;2^{+}→0^{+}) as compared to ^{68}Ni, but do not confirm the trend of large B(E2) values reported in the neighboring isotope ^{70}Ni obtained from Coulomb excitation measurement. The results are compared to shell model calculations. The lifetime obtained for the excited 4_{1}^{+} state is consistent with models showing decay of a seniority ν=4, 4^{+} state, which is consistent with the disappearance of the 8^{+} isomer in ^{72}Ni.
Collapse
Affiliation(s)
- K Kolos
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - D Miller
- TRIUMF, 4004 Westbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - R Grzywacz
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6371, USA
| | - H Iwasaki
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Al-Shudifat
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - D Bazin
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
| | - C R Bingham
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6371, USA
| | - T Braunroth
- Institut für Kernphysik der Universität zu Köln, D-50937 Köln, Germany
| | - G Cerizza
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - A Gade
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Lemasson
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
| | - S N Liddick
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Madurga
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - C Morse
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Portillo
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
| | - M M Rajabali
- TRIUMF, 4004 Westbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - F Recchia
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
| | - L L Riedinger
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6371, USA
| | - P Voss
- Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - W B Walters
- University of Maryland, College Park, Maryland 20742, USA
| | - D Weisshaar
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
| | - K Whitmore
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - K Wimmer
- Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - J A Tostevin
- Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
| |
Collapse
|
12
|
Bennett MB, Wrede C, Brown BA, Liddick SN, Pérez-Loureiro D, Bardayan DW, Chen AA, Chipps KA, Fry C, Glassman BE, Langer C, Larson NR, McNeice EI, Meisel Z, Ong W, O'Malley PD, Pain SD, Prokop CJ, Schatz H, Schwartz SB, Suchyta S, Thompson P, Walters M, Xu X. Isospin Mixing Reveals ^{30}P(p,γ)^{31}S Resonance Influencing Nova Nucleosynthesis. Phys Rev Lett 2016; 116:102502. [PMID: 27015475 DOI: 10.1103/physrevlett.116.102502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Indexed: 06/05/2023]
Abstract
The thermonuclear ^{30}P(p,γ)^{31}S reaction rate is critical for modeling the final elemental and isotopic abundances of ONe nova nucleosynthesis, which affect the calibration of proposed nova thermometers and the identification of presolar nova grains, respectively. Unfortunately, the rate of this reaction is essentially unconstrained experimentally, because the strengths of key ^{31}S proton capture resonance states are not known, largely due to uncertainties in their spins and parities. Using the β decay of ^{31}Cl, we have observed the β-delayed γ decay of a ^{31}S state at E_{x}=6390.2(7) keV, with a ^{30}P(p,γ)^{31}S resonance energy of E_{r}=259.3(8) keV, in the middle of the ^{30}P(p,γ)^{31}S Gamow window for peak nova temperatures. This state exhibits isospin mixing with the nearby isobaric analog state at E_{x}=6279.0(6) keV, giving it an unambiguous spin and parity of 3/2^{+} and making it an important l=0 resonance for proton capture on ^{30}P.
Collapse
Affiliation(s)
- M B Bennett
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Wrede
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - B A Brown
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - S N Liddick
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Pérez-Loureiro
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - D W Bardayan
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - A A Chen
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - K A Chipps
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - C Fry
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - B E Glassman
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Langer
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - N R Larson
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - E I McNeice
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Z Meisel
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - W Ong
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - P D O'Malley
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - S D Pain
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - C J Prokop
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - H Schatz
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - S B Schwartz
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Geology and Physics, University of Southern Indiana, Evansville, Indiana 47712, USA
| | - S Suchyta
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - P Thompson
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - M Walters
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - X Xu
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| |
Collapse
|
13
|
Spyrou A, Liddick SN, Larsen AC, Guttormsen M, Cooper K, Dombos AC, Morrissey DJ, Naqvi F, Perdikakis G, Quinn SJ, Renstrøm T, Rodriguez JA, Simon A, Sumithrarachchi CS, Zegers RGT. Novel technique for constraining r-process (n, γ) reaction rates. Phys Rev Lett 2014; 113:232502. [PMID: 25526121 DOI: 10.1103/physrevlett.113.232502] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Indexed: 06/04/2023]
Abstract
A novel technique has been developed, which will open exciting new opportunities for studying the very neutron-rich nuclei involved in the r process. As a proof of principle, the γ spectra from the β decay of ^{76}Ga have been measured with the SuN detector at the National Superconducting Cyclotron Laboratory. The nuclear level density and γ-ray strength function are extracted and used as input to Hauser-Feshbach calculations. The present technique is shown to strongly constrain the ^{75}Ge(n,γ)^{76}Ge cross section and reaction rate.
Collapse
Affiliation(s)
- A Spyrou
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - S N Liddick
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - A C Larsen
- Department of Physics, University of Oslo, NO-0316 Oslo, Norway
| | - M Guttormsen
- Department of Physics, University of Oslo, NO-0316 Oslo, Norway
| | - K Cooper
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - A C Dombos
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - D J Morrissey
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - F Naqvi
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - G Perdikakis
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA and Central Michigan University, Mount Pleasant, Michigan, 48859, USA
| | - S J Quinn
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics & Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - T Renstrøm
- Department of Physics, University of Oslo, NO-0316 Oslo, Norway
| | - J A Rodriguez
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Simon
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and The Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - C S Sumithrarachchi
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - R G T Zegers
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics & Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| |
Collapse
|
14
|
Tripathi V, Tabor SL, Volya A, Liddick SN, Bender PC, Larson N, Prokop C, Suchyta S, Tai PL, Vonmoss JM. Split isobaric analog state in 55Ni: case of strong isospin mixing. Phys Rev Lett 2013; 111:262501. [PMID: 24483792 DOI: 10.1103/physrevlett.111.262501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Indexed: 06/03/2023]
Abstract
Study of β+ decay of the exotic Tz=-3/2 nucleus 55Cu, via delayed γ rays, has revealed a strongly isospin mixed doublet (4599-4579 keV) in 55Ni, which represents the fragmented and previously unknown isobaric analog of the ground state of 55Cu. The observed small log ft values to both states in the doublet confirm the superallowed Fermi β decay. The near degeneracy of a pair of 3/2- levels in 55Ni results in the strong isospin mixing. The isospin mixing matrix element between the T=3/2 and T=1/2 levels is inferred from the experiment to be 9(1) keV, which agrees well with the matrix element of the charge symmetry breaking shell model Hamiltonian of Ormand and Brown. A precise value of the half-life of 55Cu at 57(3) ms was also obtained.
Collapse
Affiliation(s)
- Vandana Tripathi
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - S L Tabor
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - A Volya
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - S N Liddick
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - P C Bender
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - N Larson
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Prokop
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - S Suchyta
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - P-L Tai
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - J M Vonmoss
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| |
Collapse
|
15
|
Bennett MB, Wrede C, Chipps KA, José J, Liddick SN, Santia M, Bowe A, Chen AA, Cooper N, Irvine D, McNeice E, Montes F, Naqvi F, Ortez R, Pain SD, Pereira J, Prokop C, Quaglia J, Quinn SJ, Schwartz SB, Shanab S, Simon A, Spyrou A, Thiagalingam E. Classical-NOVA CONTRIBUTION to the Milky Way's ²⁶Al abundance: exit channel of the key ²⁵Al(p,γ) ²⁶Si resonance. Phys Rev Lett 2013; 111:232503. [PMID: 24476263 DOI: 10.1103/physrevlett.111.232503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/07/2013] [Indexed: 06/03/2023]
Abstract
Classical novae are expected to contribute to the 1809-keV Galactic γ-ray emission by producing its precursor 26Al, but the yield depends on the thermonuclear rate of the unmeasured 25Al(p,γ)26Si reaction. Using the β decay of 26P to populate the key J(π)=3(+) resonance in this reaction, we report the first evidence for the observation of its exit channel via a 1741.6±0.6(stat)±0.3(syst) keV primary γ ray, where the uncertainties are statistical and systematic, respectively. By combining the measured γ-ray energy and intensity with other experimental data on 26Si, we find the center-of-mass energy and strength of the resonance to be E(r)=414.9±0.6(stat)±0.3(syst)±0.6(lit.) keV and ωγ=23±6(stat)(-10)(+11)(lit.) meV, respectively, where the last uncertainties are from adopted literature data. We use hydrodynamic nova simulations to model 26Al production showing that these measurements effectively eliminate the dominant experimental nuclear-physics uncertainty and we estimate that novae may contribute up to 30% of the Galactic 26Al.
Collapse
Affiliation(s)
- M B Bennett
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Wrede
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - K A Chipps
- Department of Physics, Colorado School of Mines, Golden, Colorado 08401, USA
| | - J José
- Departament Física i Enginyeria Nuclear (UPC) and Institut d'Estudis Espacials de Catalunya (IEEC), E-08034 Barcelona, Spain
| | - S N Liddick
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Santia
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Bowe
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Physics Department, Kalamazoo College, Kalamazoo, Michigan 49006, USA
| | - A A Chen
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - N Cooper
- Department of Physics and Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520, USA
| | - D Irvine
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - E McNeice
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - F Montes
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - F Naqvi
- Department of Physics and Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520, USA
| | - R Ortez
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - S D Pain
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J Pereira
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Prokop
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Quaglia
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA and Department of Electrical Engineering, Michigan State University, East Lansing, Michigan 48824, USA
| | - S J Quinn
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - S B Schwartz
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Geology and Physics Department, University of Southern Indiana, Evansville, Indiana 47712, USA
| | - S Shanab
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Simon
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Spyrou
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Thiagalingam
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| |
Collapse
|
16
|
Darby IG, Grzywacz RK, Batchelder JC, Bingham CR, Cartegni L, Gross CJ, Hjorth-Jensen M, Joss DT, Liddick SN, Nazarewicz W, Padgett S, Page RD, Papenbrock T, Rajabali MM, Rotureau J, Rykaczewski KP. Orbital dependent nucleonic pairing in the lightest known isotopes of tin. Phys Rev Lett 2010; 105:162502. [PMID: 21230967 DOI: 10.1103/physrevlett.105.162502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Indexed: 05/30/2023]
Abstract
By studying the (109)Xe→(105)Te→(101)Sn superallowed α-decay chain, we observe low-lying states in (101)Sn, the one-neutron system outside doubly magic (100)Sn. We find that the spins of the ground state (J=7/2) and first excited state (J=5/2) in (101)Sn are reversed with respect to the traditional level ordering postulated for (103)Sn and the heavier tin isotopes. Through simple arguments and state-of-the-art shell-model calculations we explain this unexpected switch in terms of a transition from the single-particle regime to the collective mode in which orbital-dependent pairing correlations dominate.
Collapse
Affiliation(s)
- I G Darby
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Winger JA, Ilyushkin SV, Rykaczewski KP, Gross CJ, Batchelder JC, Goodin C, Grzywacz R, Hamilton JH, Korgul A, Królas W, Liddick SN, Mazzocchi C, Padgett S, Piechaczek A, Rajabali MM, Shapira D, Zganjar EF, Borzov IN. Large beta-delayed neutron emission probabilities in the 78Ni region. Phys Rev Lett 2009; 102:142502. [PMID: 19392431 DOI: 10.1103/physrevlett.102.142502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Indexed: 05/27/2023]
Abstract
The beta-delayed neutron branching ratios (P{betan}) for nuclei near doubly magic 78Ni have been directly measured using a new method combining high-resolution mass separation, reacceleration, and digital beta-gamma spectroscopy of 238U fission products. The P{betan} values for the very neutron-rich isotopes ;{76-78}Cu and 83Ga were found to be much higher than previously reported and predicted. Revised calculations of the betan process, accounting for new mass measurements and an inversion of the pi2p{3/2} and pi1f{5/2} orbitals, are in better agreement with these new experimental results.
Collapse
Affiliation(s)
- J A Winger
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Miernik K, Dominik W, Janas Z, Pfützner M, Grigorenko L, Bingham CR, Czyrkowski H, Cwiok M, Darby IG, Dabrowski R, Ginter T, Grzywacz R, Karny M, Korgul A, Kuśmierz W, Liddick SN, Rajabali M, Rykaczewski K, Stolz A. Two-proton correlations in the decay of 45Fe. Phys Rev Lett 2007; 99:192501. [PMID: 18233071 DOI: 10.1103/physrevlett.99.192501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Indexed: 05/25/2023]
Abstract
The decay of extremely neutron-deficient 45Fe has been studied in detail by means of a novel type of a gaseous detector employing digital imaging to record tracks of charged particles. The two-proton radioactivity channel was clearly identified. For the first time, the angular and energy correlations between two protons emitted from the nuclear ground state were determined, indicating the genuine three-body character of this decay. The half-life of 45Fe was found to be 2.6+/-0.2 ms and the observed 2p decay branching ratio is 70+/-4%.
Collapse
Affiliation(s)
- K Miernik
- Institute of Experimental Physics, Warsaw University, 00-681, Warsaw, Poland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Mazzocchi C, Grzywacz R, Liddick SN, Rykaczewski KP, Schatz H, Batchelder JC, Bingham CR, Gross CJ, Hamilton JH, Hwang JK, Ilyushkin S, Korgul A, Królas W, Li K, Page RD, Simpson D, Winger JA. Alpha decay of 109I and its implications for the proton decay of 105Sb and the astrophysical rapid proton-capture process. Phys Rev Lett 2007; 98:212501. [PMID: 17677769 DOI: 10.1103/physrevlett.98.212501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Indexed: 05/16/2023]
Abstract
An alpha-decay branch of (1.4+/-0.4) x 10(-4) has been discovered in the decay of 109I, which predominantly decays via proton emission. The measured Q(alpha) value of 3918+/-21 keV allows the indirect determination of the Q value for proton emission from 105Sb of 356+/-22 keV, which is approximately of 130 keV more bound than previously reported. This result is relevant for the astrophysical rapid proton-capture process, which would terminate in the 105Sn(p,gamma)106Sb(p,gamma)107Te(alpha decay)103Sn cycle at the densities expected in explosive hydrogen burning scenarios, unless unusually strong pairing effects result in a 103Sn(p,gamma)104Sb(p,gamma)105Te(alpha decay)101Sn) cycle.
Collapse
Affiliation(s)
- C Mazzocchi
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Liddick SN, Grzywacz R, Mazzocchi C, Page RD, Rykaczewski KP, Batchelder JC, Bingham CR, Darby IG, Drafta G, Goodin C, Gross CJ, Hamilton JH, Hecht AA, Hwang JK, Ilyushkin S, Joss DT, Korgul A, Królas W, Lagergren K, Li K, Tantawy MN, Thomson J, Winger JA. Discovery of 109Xe and 105Te: superallowed alpha decay near doubly magic 100Sn. Phys Rev Lett 2006; 97:082501. [PMID: 17026296 DOI: 10.1103/physrevlett.97.082501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 06/23/2006] [Indexed: 05/12/2023]
Abstract
Two new alpha emitters 109Xe and 105Te were identified through the observation of the 109Xe --> 105Te --> 101Sn alpha-decay chain. The 109Xe nuclei were produced in the fusion-evaporation reaction 54Fe(58Ni,3n)109Xe and studied using the Recoil Mass Spectrometer at the Holifield Radioactive Ion Beam Facility. Two transitions at Ealpha = 4062 +/- 7 keV and Ealpha = 3918 +/- 9 keV were interpreted as the l = 2 and l = 0 transitions from the 7/2+ ground state in 109Xe (T1/2 = 13 +/- 2 ms) to the 5/2+ ground state and a 7/2+ excited state, located at 150 +/- 13 keV in 105Te. The observation of the subsequent decay of 105Te marks the discovery of the lightest known alpha-decaying nucleus. The measured transition energy Ealpha = 4703 +/- 5 keV and half-life T1/2 = 620 +/- 70 ns were used to determine the reduced alpha-decay width delta2. The ratio delta105Te(2)/delta213Po(2) of approximately 3 indicates a superallowed character of the alpha emission from 105Te.
Collapse
Affiliation(s)
- S N Liddick
- UNIRIB, Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Davies AD, Stuchbery AE, Mantica PF, Davidson PM, Wilson AN, Becerril A, Brown BA, Campbell CM, Cook JM, Dinca DC, Gade A, Liddick SN, Mertzimekis TJ, Mueller WF, Terry JR, Tomlin BE, Yoneda K, Zwahlen H. Probing shell structure and shape changes in neutron-rich sulfur isotopes through transient-field g-factor measurements on fast radioactive beams of 38S and 40S. Phys Rev Lett 2006; 96:112503. [PMID: 16605815 DOI: 10.1103/physrevlett.96.112503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2005] [Indexed: 05/08/2023]
Abstract
The shell structure underlying shape changes in neutron-rich nuclei near N = 28 has been investigated by a novel application of the transient-field technique to measure the first-excited-state g factors in 38S and 40S produced as fast radioactive beams. There is a fine balance between proton and neutron contributions to the magnetic moments in both nuclei. The g factor of deformed 40S does not resemble that of a conventional collective nucleus because spin contributions are more important than usual.
Collapse
Affiliation(s)
- A D Davies
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Tripathi V, Tabor SL, Mantica PF, Hoffman CR, Wiedeking M, Davies AD, Liddick SN, Mueller WF, Otsuka T, Stolz A, Tomlin BE, Utsuno Y, Volya A. 29Na: defining the edge of the island of inversion for Z=11. Phys Rev Lett 2005; 94:162501. [PMID: 15904217 DOI: 10.1103/physrevlett.94.162501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2004] [Indexed: 05/02/2023]
Abstract
The low-energy level structure of the exotic Na isotopes (28,29)Na has been investigated through beta-delayed gamma spectroscopy. The N=20 isotones for Z=10-12 are considered to belong to the "island of inversion" where intruder configurations dominate the ground state wave function. However, it is an open question as to where and how the transition from normal to intruder dominated configurations happens in an isotopic chain. The present work, which presents the first detailed spectroscopy of (28,29)Na, clearly demonstrates that such a transition in the Na isotopes occurs between 28Na (N=17) and 29Na (N=18), supporting the smaller N=20 shell gap in neutron-rich sd shell nuclei. The evidence for inverted shell structure is found in beta-decay branching ratios, intruder dominated spectroscopy of low-lying states, and shell model analysis.
Collapse
Affiliation(s)
- Vandana Tripathi
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Hosmer PT, Schatz H, Aprahamian A, Arndt O, Clement RRC, Estrade A, Kratz KL, Liddick SN, Mantica PF, Mueller WF, Montes F, Morton AC, Ouellette M, Pellegrini E, Pfeiffer B, Reeder P, Santi P, Steiner M, Stolz A, Tomlin BE, Walters WB, Wöhr A. Half-life of the doubly magic r-process nucleus 78Ni. Phys Rev Lett 2005; 94:112501. [PMID: 15903849 DOI: 10.1103/physrevlett.94.112501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2004] [Indexed: 05/02/2023]
Abstract
Nuclei with magic numbers serve as important benchmarks in nuclear theory. In addition, neutron-rich nuclei play an important role in the astrophysical rapid neutron-capture process (r process). 78Ni is the only doubly magic nucleus that is also an important waiting point in the r process, and serves as a major bottleneck in the synthesis of heavier elements. The half-life of 78Ni has been experimentally deduced for the first time at the Coupled Cyclotron Facility of the National Superconducting Cyclotron Laboratory at Michigan State University, and was found to be 110(+100)(-60) ms. In the same experiment, a first half-life was deduced for 77Ni of 128(+27)(-33) ms, and more precise half-lives were deduced for 75Ni and 76Ni of 344(+20)(-24) ms and 238(+15)(-18) ms, respectively.
Collapse
Affiliation(s)
- P T Hosmer
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Liddick SN, Mantica PF, Janssens RVF, Broda R, Brown BA, Carpenter MP, Fornal B, Honma M, Mizusaki T, Morton AC, Mueller WF, Otsuka T, Pavan J, Stolz A, Tabor SL, Tomlin BE, Wiedeking M. Lowest excitations in 56Ti and the predicted N=34 shell closure. Phys Rev Lett 2004; 92:072502. [PMID: 14995845 DOI: 10.1103/physrevlett.92.072502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2003] [Indexed: 05/24/2023]
Abstract
Recent experimental characterization of the subshell closure at N=32 in the Ca, Ti, and Cr isotones has stimulated shell-model calculations that indicated the possibility that the N=34 isotones of these same elements could exhibit characteristics of a shell closure, namely, a high energy for the first excited 2(+) level. To that end, we have studied the decay of 56Sc produced in fragmentation reactions and identified new gamma rays in the daughter N=34 isotone 56Ti. The first 2(+) level is found at an energy of 1127 keV, well below the expected position that would indicate the presence of an N=34 shell closure in 56Ti.
Collapse
Affiliation(s)
- S N Liddick
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Groh DE, Mantica PF, Stuchbery AE, Stolz A, Mertzimekis TJ, Rogers WF, Davies AD, Liddick SN, Tomlin BE. Spin polarization of 37K produced in a single-proton pickup reaction at intermediate energies. Phys Rev Lett 2003; 90:202502. [PMID: 12785888 DOI: 10.1103/physrevlett.90.202502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2003] [Indexed: 05/24/2023]
Abstract
Spin polarization of 37K nuclei produced via single proton pickup from a 9Be target by a beam of 150 MeV/nucleon 36Ar has been observed. Positive spin polarization with magnitude (8.5+/-0.6)% was deduced near the peak of the 37K momentum distribution. The variation of the spin polarization as a function of outgoing 37K momentum is explained by a classical conservation model, as previously applied to describe the induced spin polarization observed for fragments produced in intermediate-energy heavy-ion reactions, with the condition that the picked-up proton has an average momentum equal to the Fermi momentum and is aligned along the incident beam direction.
Collapse
Affiliation(s)
- D E Groh
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | | | | | | | | | | | | | | | | |
Collapse
|