Half-lives and branchings for {beta}-delayed neutron emission for neutron-rich Co-Cu isotopes in the r-process

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.82.025806· OSTI ID:21420887

Hosmer, P; Estrade, A; Montes, F; Ouellette, M; Pellegrini, E ^[1]; Schatz, H ^[1]; Aprahamian, A ^[2]; Arndt, O; Pfeiffer, B ^[3]; Clement, R R. C.; Mueller, W F; Morton, A C; Pereira, J; Santi, P; Steiner, M; Stolz, A ^[1]; Farouqi, K ^[4]; Kratz, K -L ^[5]; Liddick, S N; Mantica, P F ^[1]

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1. National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)
2. Department of Physics and Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
3. Institut fuer Kernchemie, Universitaet Mainz, Fritz-Strassmann Weg 2, D-55128 Mainz (Germany)
4. Department of Astronomy and Astrophysics and Joint Institute for Nuclear Astrophysics, University of Chicago, Chicago, IL 60637 (United States)
5. HGF Virtuelles Institut fuer Kernstruktur und Nukleare Astrophysik (Germany)

The {beta} decays of very neutron-rich nuclides in the Co-Zn region were studied experimentally at the National Superconducting Cyclotron Laboratory using the NSCL {beta}-counting station in conjunction with the neutron detector NERO. We measured the branchings for {beta}-delayed neutron emission (P{sub n} values) for {sup 74}Co (18{+-}15%) and {sup 75-77}Ni (10{+-}2.8%, 14{+-}3.6%, and 30{+-}24%, respectively) for the first time, and remeasured the P{sub n} values of {sup 77-79}Cu, {sup 79,81}Zn, and {sup 82}Ga. For {sup 77-79}Cu and for {sup 81}Zn we obtain significantly larger P{sub n} values compared to previous work. While the new half-lives for the Ni isotopes from this experiment had been reported before, we present here in addition the first half-life measurements of {sup 75}Co (30{+-}11 ms) and {sup 80}Cu (170{sub -50}{sup +110} ms). Our results are compared with theoretical predictions, and their impact on various types of models for the astrophysical rapid neutron-capture process (r-process) is explored. We find that with our new data, the classical r-process model is better able to reproduce the A=78-80 abundance pattern inferred from the solar abundances. The new data also influence r-process models based on the neutrino-driven high-entropy winds in core collapse supernovae.

• OSTI ID: 21420887
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 82, Issue 2; Other Information: DOI: 10.1103/PhysRevC.82.025806; (c) 2010 The American Physical Society; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ASTROPHYSICS
BETA DECAY
BRANCHING RATIO
COBALT 74
COBALT 75
COPPER 77
COPPER 78
COPPER 79
COPPER 80
COUPLING
DELAYED NEUTRONS
EMISSION
ENTROPY
FORECASTING
GALLIUM 82
HALF-LIFE
NEUTRINOS
NEUTRON DETECTORS
NEUTRON EMISSION
NEUTRON REACTIONS
NEUTRON-RICH ISOTOPES
NICKEL 75
NICKEL 76
NICKEL 77
NICKEL ISOTOPES
R PROCESS
SUPERCONDUCTING CYCLOTRONS
SUPERNOVAE
ZINC 79
ZINC 81
ACCELERATORS
BARYON REACTIONS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BINARY STARS
COBALT ISOTOPES
COPPER ISOTOPES
CYCLIC ACCELERATORS
CYCLOTRONS
DECAY
DIMENSIONLESS NUMBERS
ELEMENTARY PARTICLES
ERUPTIVE VARIABLE STARS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EVOLUTION
FERMIONS
FISSION NEUTRONS
GALLIUM ISOTOPES
HADRON REACTIONS
HADRONS
INTERMEDIATE MASS NUCLEI
ISOTOPES
LEPTONS
MASSLESS PARTICLES
MEASURING INSTRUMENTS
MILLISECONDS LIVING RADIOISOTOPES
NEUTRONS
NUCLEAR DECAY
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUCLEONS
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
PHYSICAL PROPERTIES
PHYSICS
RADIATION DETECTORS
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
STAR EVOLUTION
STARS
THERMODYNAMIC PROPERTIES
VARIABLE STARS
ZINC ISOTOPES