{sup 19}Ne and breakout from the hot CNO cycle

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Bulletin of the American Physical Society

OSTI ID:243702

Utku, S; Bateman, N; Lund, B J ^[1]

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1. and others

At sufficiently high temperatures, the {beta}{sup +} decay of {sup 14}O can be bypassed in the HCNO cycle by the reaction sequence {sup 14}O({alpha},p){sup 17}F(p,{gamma}){sup 18}Ne({beta}{sup +}{nu}){sup 18}F, and breakout from this cycle is then possible via either the {sup 18}F(p,{gamma}){sup 19}Ne or the {sup 18}F(p,{alpha}){sup 15}O({alpha},{gamma}){sup 19}Ne reactions. A direct determination of the relative rates of these breakout paths is possible by a measurement of the {alpha},p, and {gamma} decay widths of the appropriate resonances. The authors have measured accurate excitation energies ({+-}8 keV) and {Gamma}{sub p}/{Gamma}{sub {alpha}} decay ratios for {sup 19}Ne states just above the {sup 18}F+p threshold. The states of interest were populated using the {sup 19}F({sup 3}He,t){sup 19}Ne reaction at a beam energy of 30 MeV using the Princeton Cyclotron and its associated QDDD spectrometer. Coincident {alpha}-particles and protons were detected using an array of Si(SB) detectors. Branching ratios {Gamma}{sub p}/{Gamma}{sub {alpha}} of 0.58(8), 2.7(9), 0.29(9), and 0.34(5) were measured for {sup 19}Ne states at E{sub x}=7.060/7.088, 7.500, 7.531, 7.620 MeV, respectively. Astrophysical implications of these results will be discussed.

• OSTI ID: 243702
• Report Number(s): CONF-9304297--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 2 Vol. 38; ISSN BAPSA6; ISSN 0003-0503
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BRANCHING RATIO
CNO CYCLE
EXCITED STATES
FLUORINE 19 TARGET
HELIUM 3 REACTIONS
MEV RANGE 10-100
NEON 19
TRITONS