The rp-process waiting-point nucleus 68Se and its astrophysical implications

✍ Scribed by A. Wöhr; A. Aprahamian; P. Boutachkov; J.L. Galache; J. Görres; M. Shawcross; A. Teymurazyan; M.C. Wiescher; D.S. Brenner; C.N. Davids; S.M. Fischer; A.M. Heinz; R.V.F. Janssens; D. Seweryniak

• Book ID: 103865331
• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 432 KB
• Volume: 742
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/j.nuclphysa.2004.06.024

✦ Synopsis

Precise mass measurements of nuclei along the N = Z line are important input parameters for simulations of the rp-process. Of particular interest is the mass of the 68 34 Se 34 rp-process waiting point nucleus for determining the possibility of a two-proton capture branch bypassing its slow β-decay. The mass of 68 Se was measured via the β-decay endpoint. 68 Se was produced by the 12 C( 58 Ni, 2n) 68 Se reaction and subsequently implanted onto a moving tape system using the fragment mass analyzer at the ATLAS facility of Argonne National Laboratory. A mass excess value of (-54189 ± 240) keV was determined from the β-endpoint measurement of Q EC = 4710(200) keV. Evaluations of proton separation energies based on the measured mass were used in a one zone type I X-ray burst model. It is concluded that the N = Z = 34 isotope 68 Se is a waiting point for the rp-process.