The astrophysically important 3+ state in 18Ne and the 17F(py)18Ne stellar rate

Authors :: Woods, P.J.
Blackmon, J.C.
Rabban, M.T.
Chen, A.A.
Pierce, D.E.
Kozub, R.L.
Champagne, A.E.
Smith, M.S.
Hofstee, M.A.
Hansper, V.Y.
Shotter, A.C.
Swartz, K.B.
Johnson, B.A.
Bardayan, D.W.
Davinson, T.
Cox, J.M.
Parker, P.D.
Ma, Z.
Brune, C.R.
Visser, D.W.
Publication Year :: 2000
Publisher :: American Physical Society, 2000.
Abstract: Knowledge of the [Formula Presented] reaction rate is important for understanding stellar explosions, but it was uncertain because the properties of an expected but previously unobserved [Formula Presented] state in [Formula Presented] were not known. This state would provide a strong s-wave resonance for the [Formula Presented] system and, depending on its excitation energy, could dominate the stellar reaction rate at temperatures above 0.2 GK. We have observed this missing [Formula Presented] state by measuring the [Formula Presented] excitation function with a radioactive [Formula Presented] beam at the ORNL Holifield Radioactive Ion Beam Facility (HRIBF). We find that the state lies at a center-of-mass energy of [Formula Presented] keV [Formula Presented] and has a width of [Formula Presented] The measured properties of the resonance are only consistent with a [Formula Presented] assignment.