ONE-PROTON BREAKUP OF 18F AND THE 17O(P,GAMMA)18F REACTION IN CLASSICAL NOVAE

Classical novae are fascinating stellar explosions. Their study is of considerable interest for understanding the chemical evolution of the Galaxy. In fact they have been proposed [1] as the most significant source for the nucleosynthesis of the isotopes 13C, 15N, and 17O in the Universe. Novae are also likely to synthesize the short-lived radioisotope 18F (T1/2 = 110 min), which is expected to be the most important contributor to the observed emission of 511 keV gamma radiation by space-based gamma-ray telescopes. This emission is produced by electron-positron annihilation following the beta+ decay of radioactive nuclei. A detection of these gamma rays could significantly constrain the nova simulation models. 18F nucleosynthesis in classical novae strongly depends on the thermonuclear rate of the 17O(p,gamma)18F reaction, which is part of the CNO cycle [2]. This work presents preliminary results toward determination of the 17O(p,gamma)18F reaction cross section, which was measured by the indirect method of one-proton nuclear breakup at intermediate energies [3]. The experiment was carried out at GANIL, in France, using a beam of 18F at 40 MeV/nucleon impinging on a carbon target. Longitudinal momentum distributions of the 17O breakup fragments were measured in coincidence with gamma rays emitted by 17O residues, left excited after the one-proton breakup of 18F. [1] J. Jose and M. Hernaz, Astrophys. J. 494 (1998) 680. [2] C. E. Rolfs and W. S. Rodney, Cauldrons in the Cosmos (The University of Chicago Press, Chicago, 1988.) [3] A. Banu, L. Trache, F. Carstoiu et al., Phys. Rev. C 84 (2011) 015803.

Additional Abstract Information

Student(s): Brent Glassman

Department: Physics and Astronomy

Faculty Advisor: Dr. Adriana Banu

Type: Oral

Year: 2013