Ground-state proton decay of 69Br and implications for the 68Se astrophysical rp-process waiting point

Journal Article · Sat Jan 01 04:00:00 EST 2011 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.106.252503· OSTI ID:1019373

Rogers, Andrew M ^[1]; Famiano, Micahel ^[2]; Lynch, William ^[3]; Shapira, Dan ^[4]

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1. Argonne National Laboratory (ANL)
2. Western Michigan University
3. Michigan State University, East Lansing
4. ORNL

We report on the first direct measurement of the proton separation energy for the proton-unbound nucleus {sup 69}Br. Bypassing the {sup 68}Se waiting point in the rp process is directly related to the 2p-capture rate through {sup 69}Br, which depends exponentially on the proton separation energy. We find a proton separation energy for {sup 69}Br of S{sub p}({sup 69}Br) = -785{sub -40}{sup +34} keV; this is less bound compared to previous predictions which have relied on uncertain theoretical calculations. The influence of the extracted proton separation energy on the rp process occurring in type I x-ray bursts is examined within the context of a one-zone burst model.

• Research Organization: Oak Ridge National Laboratory (ORNL); Other RIB Facility
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1019373
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 25 Vol. 106; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BINDING ENERGY
BROMINE 69
DECAY
PROTONS
SELENIUM 68