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Evolution of shell gaps in the neutron-poor calcium region from invariant-mass spectroscopy of 37,38Sc, 35Ca, 34K

Journal Article · · Physical Review. C
 [1];  [2];  [2];  [3];  [3];  [3];  [3];  [4];  [3];  [3];  [3];  [3];  [3];  [3];  [3];  [3];  [3];  [3];  [3]
  1. Washington University in St. Louis, MO (United States); Washington University in St. Louis
  2. Washington University in St. Louis, MO (United States)
  3. Michigan State University, East Lansing, MI (United States)
  4. Argonne National Laboratory (ANL), Argonne, IL (United States)
+ Show Author Affiliations

A fast secondary beam of 37Ca impinged on a 9Be target resulting in a set of reactions populating proton-rich nuclei including 35Ca and the first observations of 37,38Sc and 34K. Invariant-mass spectroscopy, used to reconstruct proton decays for these nuclei, yielded three new ground-state masses and information on their low-lying structures. The newly measured mass excesses are: ΔM(37Sc) = 3500(410) keV, ΔM(38Sc) = –4656(14) keV, and ΔM(34K) = –1487(17) keV. These nuclei straddle the well-known Z = 20 shell closure as well as the N = 16 subshell closure. Furthermore, trends in separation energies help elucidate how nuclear structure evolves showing a fading of the Z = 20 shell gap for N ≥ 18 and indications of a N = 16 subshell gap.

Research Organization:
Washington University in St. Louis, MO (United States); Michigan State University, East Lansing, MI (United States); Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP); USDOE National Nuclear Security Administration (NNSA); National Science Foundation (NSF)
Grant/Contract Number:
FG02-87ER40316; SC0020451; SC0023633; AC02-06CH11357; NA0003180
OSTI ID:
2441307
Journal Information:
Physical Review. C, Journal Name: Physical Review. C Journal Issue: 3 Vol. 110; ISSN 2469-9985
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

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Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
binding energy
energy levels
mass
new isotopes
nuclear structure
proton emission
rare isotopes