Study of Interference Effects in the ¹⁸F(p,alpha)¹⁵O Reaction

Conference · Sun Jan 01 00:00:00 EST 2006

OSTI ID:944098

Chae, Kyung Yuk ^[1]; Bardayan, Daniel W ^[1]; Blackmon, Jeff C ^[1]; Gregory, Darren R ^[1]; Guidry, Mike W ^[1]; Johnson, Micah ^[1]; KOZUB, RAYMOND L ^[1]; Livesay, Jake ^[1]; Ma, Zhanwen ^[1]; Nesaraja, Caroline D ^[1]; Pain, Steven D ^[1]; Paulauskas, Stanley V ^[1]; Porter-Peden, Matthew D ^[1]; Smith, Michael Scott ^[1]; Smith, Nathan A ^[1]; Thomas, Jeffrey S ^[1]

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1. ORNL

The {sup 18}F(p,{alpha}a){sup 15}O reaction plays a crucial role in understanding {gamma}-ray emission from novae. Because of the importance of understanding the {sup 18}F + p reactions, a number of studies of the A=19 isobars have been made using stable and exotic beams. The interference effects among J{sup {pi}} = 3/2{sup +} resonances in the {sup 18}F + p system, however, have never been measured, but they can change the S-factor by a factor of 20 at nova energies. R-matrix calculations indicate that the cross sections above the E{sub c.m.} = 665 keV resonance are sensitive to the interference between the E{sub c.m.} = 8, 38, and 665 keV resonances. In order to study the interference effects, an excitation function for the {sup 1}H({sup 18}F,{alpha}){sup 15}O reaction has been measured in the energy range of E{sub c.m.} = 663-877 keV using radioactive {sup 18}F beams at the Holifield Radioactive Ion Beam Facility. By measuring the {sup 18}F(p,{alpha}){sup 15}O cross section off resonance and comparing the cross section with theoretical calculations, we provide the first experimental constraints on the interference of 3/2{sup +} resonances.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Holifield Radioactive Ion Beam Facility (HRIBF)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 944098
• Resource Relation: Conference: International Symposium on Nuclear Astrophysics - Nuclei in the Cosmos IX, Geneva, Switzerland, 20060625, 20060630
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASTROPHYSICS
CROSS SECTIONS
ENERGY RANGE
EXCITATION FUNCTIONS
NOVAE
NUCLEI
R MATRIX
RADIOACTIVE ION BEAMS
RESONANCE
UNIVERSE