Simultaneous measurement of the {sup 18}F(p,p){sup 18}F and {sup 18}F(p,{alpha}){sup 15}O reactions: Implications for the level structure of {sup 19}Ne, and for {sup 18}F production in novae

Journal Article · Fri May 15 04:00:00 EDT 2009 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.79.058801· OSTI ID:21286991

Murphy, A St. J.; Davinson, T ^[1]; Laird, A M; Fox, S P; Lewis, R; Vaughan, K ^[2]; Angulo, C ^[3]; Buchmann, L; Ruiz, C; Walden, P ^[4]; Descouvemont, P ^[5]; Jose, J ^[6]

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1. School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom)
2. Department of Physics, University of York, York YO10 5DD (United Kingdom)
3. Tractebel Engineering, Avenue Ariane 7, B-1200 Brussels (Belgium)
4. TRIUMF, Vancouver, V6T 2A3 (Canada)
5. Physique Nucleaire Theorique et Physique Mathematique, CP229, Universite Libre de Bruxelles, B-1050 Brussels (Belgium)
6. Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, E-08036 and Institut d'Estudis Espacials de Catalunya, E-08034, Barcelona (Spain)

The largest nuclear physics uncertainty in studies of gamma-ray emission from novae arises from the {sup 18}F(p,{alpha}){sup 15}O reaction rate that affects the abundance of {sup 18}F. Direct measurements have been made of the {sup 18}F(p,p){sup 18}F and {sup 18}F(p,{alpha}){sup 15}O reaction differential cross sections in the energy range 0.6{<=}E{sub c.m.}{<=}1.6 MeV. Several resonances have been observed in both measurements, with simultaneous R-matrix fits used to determine the properties of corresponding states in {sup 19}Ne. A recently reported state at 7.420 MeV is not seen, while new states are seen including one of J{sup {pi}}=(3/2){sup +}. A candidate for a recently predicted broad J{sup {pi}}=(1/2){sup +} state is seen, which would have significant impact on the low energy {sup 18}F(p,{alpha}){sup 15}O reaction rate, but its alpha width is significantly smaller than expected.

• OSTI ID: 21286991
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 5 Vol. 79; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY
DIFFERENTIAL CROSS SECTIONS
EMISSION
FLUORINE 18
GAMMA RADIATION
MEV RANGE 01-10
NEON 19
NOVAE
NUCLEAR PHYSICS
OXYGEN 15
PROTON-EMISSION DECAY
PROTONS
R MATRIX
REACTION KINETICS
RESONANCE