Search for a state at E{sub x} = 2.6 MeV in {sup 20}Na via the {sup 20}Ne(p,n) {sup 20}Na reaction and possible breakout from the hot CNO cycle

Journal Article · Fri Oct 01 04:00:00 EDT 1993 · Bulletin of the American Physical Society

OSTI ID:387168

Anderson, B D; Wetmore, B; Baldwin, A R ^[1]

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1. and others

At the high temperatures and densities present in supernovae explosions, hydrogen burning proceeds through the hot CNO cycle. At temperatures, T > 1 x 10{sup 8}K, this cycle may branch out through the reaction sequence {sup 15}O({alpha},{gamma}) {sup 19}Ne (p,{gamma}){sup 20}Na and begin a sequence of rapid proton captures and beta decays which can process CNO nuclei to form heavier elements and can increase energy production and will alter the elemental abundances of A = 20 to 30 nuclei significantly. The strength of this breakout is very sensitive to resonances in the {sup 19}Ne + p system, i.e., states in {sup 20}Na near the proton threshold of 2.199 MeV. A state was observed in the {sup 20}Ne({sup 3}He,t){sup 20}Na reaction at 2.6 MeV and reported to most likely be a 1{sup +} state. We performed a good resolution ({Delta}E {approx} 250 keV), low-background measurement of the {sup 20}Ne(p,n){sup 20}Na reaction at 135 MeV with the IUCF beam-swinger facility. We see no evidence for a 1{sup +} state in this experiment at 2.6 MeV; in fact, any state at 2.6 MeV is excited only weakly in the (p,n) reaction. Possible limits will be discussed.

• OSTI ID: 387168
• Report Number(s): CONF-931044--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 9 Vol. 38; ISSN BAPSA6; ISSN 0003-0503
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CNO CYCLE
HELIUM 3 REACTIONS
NEON 20 TARGET
PROTON REACTIONS
SUPERNOVAE