Lifetime of the astrophysically important 4.03-MeV state in {sup 19}Ne
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
The {sup 15}O({alpha},{gamma}){sup 19}Ne reaction is one of the most important breakout reactions for the hot CNO cycles. However, the relevant states in {sup 19}Ne at excitation energies of 4-5 MeV have not been well studied. The lifetimes of these states are not known and are only constrained by experimental upper and lower limits. In particular, accurate knowledge of the {gamma}- and {alpha}-decay widths of the 4.03-MeV state of {sup 19}Ne is important, since the resonance strength of this level dominates the reaction rate for the astrophysically relevant temperatures T{sub 9}<0.6. In this work, we employed an improved Doppler-shifted attenuation method to obtain lifetime values of this and other states via {sup 17}O({sup 3}He, n-{gamma}){sup 19}Ne. For the 4.03-MeV state, the measured excitation energy is 4034.5{+-}0.8 keV and the mean lifetime, measured here for the first time, is 13{sub -6}{sup +9} fs at the confidence level of 1{sigma} and 13{sub -9}{sup +16} fs at the confidence level of 2{sigma}. This result is in excellent agreement with the 9-fs prediction by Langanke, Wiescher, Fowler, and Goerres.
- OSTI ID:
- 20699032
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 72, Issue 4; Other Information: DOI: 10.1103/PhysRevC.72.041302; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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