Spectroscopic study of low-lying N16 levels

D. W. Bardayan, ORNL Physics Division
P. D. O'Malley, Rutgers University–New Brunswick
J. C. Blackmon, Louisiana State University
K. Y. Chae, The University of Tennessee, Knoxville
K. A. Chipps, Colorado School of Mines
J. A. Cizewski, Rutgers University–New Brunswick
R. Hatarik, Rutgers University–New Brunswick
K. L. Jones, The University of Tennessee, Knoxville
R. L. Kozub, Tennessee Technological University
C. Matei, Oak Ridge Associated Universities
B. H. Moazen, The University of Tennessee, Knoxville
C. D. Nesaraja, ORNL Physics Division
S. D. Pain, ORNL Physics Division
S. Paulauskas, The University of Tennessee, Knoxville
W. A. Peters, Rutgers University–New Brunswick
S. T. Pittman, The University of Tennessee, Knoxville
K. T. Schmitt, The University of Tennessee, Knoxville
J. F. Shriner, Tennessee Technological University
M. S. Smith, ORNL Physics Division

Abstract

The magnitude of the 15N(n,γ)16N reaction rate in asymptotic giant branch stars depends directly on the neutron spectroscopic factors of low-lying N16 levels. A new study of the 15N(d,p)16N reaction is reported populating the ground and first three excited states in N16. The measured spectroscopic factors are near unity as expected from shell model calculations, resolving a long-standing discrepancy with earlier measurements that had never been confirmed or understood. Updated 15N(n,γ)16N reaction rates are presented. © 2008 The American Physical Society.