Search for astrophysically important Ne-19 levels with a thick-target F-18(p,p)F-18 measurement


Bardayan D., Blackmon J., del Campo J., Kozub R., Liang J., Ma Z., ...Daha Fazla

PHYSICAL REVIEW C, cilt.70, 2004 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

The rates of the F-18(p, alpha) O-15 and F-18(p, gamma) Ne-19 reactions in astrophysical environments depend on the properties of Ne-19 levels above the F-18+p threshold. There are at least eight levels in the mirror nucleus F-19 for which analogs have not been observed in Ne-19 in the excitation energy range E-x=6.4-7.6 MeV. These levels may significantly enhance the F-18+p reaction rates, and thus we have made a search for these levels by measuring the H-1(F-18,p) F-18 excitation function over the energy range E-c.m.=0.3-1.3 MeV. We have identified and measured the properties of a newly observed level at E-x=7.420 +/- 0.014 MeV, which is most likely the mirror to the J(pi) = 7/2 + F-19 level at 7.56 MeV. We have additionally found a significant discrepancy with a recent compilation for the properties of a Ne-19 state at E-x=7.5 MeV and set upper limits on the proton widths of missing levels.