The beta -delayed alpha spectrum of16N and the low-energy extrapolation of the12C( alpha , gamma )16O cross section

Autor: G. Roy, A. Chen, P. R. Wrean, J. Powell, L. Buchmann, P. McNeely, Ulrich Giesen, M. Dombsky, C. A. Barnes, J. Vincent, John D'Auria, J. D. King, M. Trinczek, Jun Chen, R. E. Azuma, Ralph G. Korteling, S.S.M. Wong, K. P. Jackson
Rok vydání: 1993
Předmět:
Zdroj: Journal of Physics G: Nuclear and Particle Physics. 19:S115-S126
ISSN: 1361-6471
0954-3899
Popis: The low-energy part of the beta alpha -decay spectrum of 16N permits the determination of the reduced alpha -width theta alpha 2 of the 7.12 MeV subthreshold state of 16O, which dominates the low-energy p-wave capture amplitude of the astrophysically important reaction 12C( alpha , gamma )16O. In a first run, a total of 7.1*103 alpha particles from the decay of 16N nuclei, selected by the TRIUMF isotope separator. TISOL, have been observed in a 10.6 mu m detector in coincidence with the recoiling 12C nuclei in a second detector, thus removing most sources of low-energy alpha background. These new data show a narrower width for the main alpha peak than previously determined. In addition, there is an indication of the low-energy interference anomaly predicted by several authors. The spectrum obtained can be parameterized in K- and R-matrix calculations, which also include the previously-measured 12C( alpha , gamma )16O cross sections and elastic scattering phase shifts. Results of a data collection run in June with much higher alpha yields will be presented.
Databáze: OpenAIRE