학술논문
New Constraints on the 18F(p,alpha) 15O Rate in Novae from the (d,p) Reaction
Document Type
Working Paper
Author
Kozub, R. L.; Bardayan, D. W.; Batchelder, J. C.; Blackmon, J. C.; Brune, C. R.; Champagne, A. E.; Cizewski, J. A.; Davinson, T.; Greife, U.; Gross, C. J.; Jewett, C. C.; Livesay, R. J.; Ma, Z.; Moazen, B. H.; Nesaraja, C. D.; Sahin, L.; Scott, J. P.; Shapira, D.; Smith, M. S.; Thomas, J. S.; Woods, P. J.
Source
Phys.Rev. C71 (2005) 032801
Subject
Language
Abstract
The degree to which the (p,gamma) and (p,alpha) reactions destroy 18F at temperatures 1-4x10^8 K is important for understanding the synthesis of nuclei in nova explosions and for using the long-lived radionuclide 18F, a target of gamma-ray astronomy, as a diagnostic of nova mechanisms. The reactions are dominated by low-lying proton resonances near the 18F+p threshold (E_x=6.411 MeV in 19Ne). To gain further information about these resonances, we have used a radioactive 18F beam from the Holifield Radioactive Ion Beam Facility to selectively populate corresponding mirror states in 19F via the inverse d(18F,p)19F neutron transfer reaction. Neutron spectroscopic factors were measured for states in 19F in the excitation energy range 0-9 MeV. Widths for corresponding proton resonances in 19Ne were calculated using a Woods-Saxon potential. The results imply significantly lower 18F(p,gamma)19Ne and 18F(p,alpha)15O reaction rates than reported previously, thereby increasing the prospect of observing the 511-keV annihilation radiation associated with the decay of 18F in the ashes ejected from novae.
Comment: Error involving sum rule was corrected. Proton widths were recalculated using a Woods-Saxon potential. Both low-lying resonances (8- and 38-keV) are now included in the rate band. 12 pages, 4 figures, 1 table. Submitted to Phys. Rev. C
Comment: Error involving sum rule was corrected. Proton widths were recalculated using a Woods-Saxon potential. Both low-lying resonances (8- and 38-keV) are now included in the rate band. 12 pages, 4 figures, 1 table. Submitted to Phys. Rev. C