Experimental evidence of a natural parity state in $^{26}Mg$ at astrophysically relevant energies via the $^{22}Ne(^{6}Li,d)^{26}Mg$ reaction.

ORAL

Abstract

The $^{22}Ne(\alpha,n)^{25}Mg$ reaction has been regarded as the main neutron source for the s-process in core He-burning massive stars and of relevance in He-shell burning in AGB stars. Its present rate is one of the most important sources of uncertainty in the nucleosynthesis of heavy elements. We have studied natural parity states in $^{26}$Mg via the $^{22}Ne(^{6}Li,d)^{26}Mg$ direct process with Yale University's Enge split-pole spectrograph. Our method significantly improves the energy resolution of previous experiments and as a result we report the observation of a natural parity state in $^{26}Mg$ at an energy where the stellar rate of the $^{22}Ne(\alpha,\gamma)^{26}Mg$ reaction may be reduced. This fact gives place to an increase in the production of weak component s-process neutrons via the $^{22}Ne(\alpha,n)^{25}Mg$ reaction. Possible spin-parity assignments are suggested as well.

Authors

  • C. Ugalde

    • University of North Carolina
  • A. Champagne

    • University of North Carolina
  • S. Daigle

    • University of North Carolina
  • C. Iliadis

    • University of North Carolina
  • J. Newton

    • University of North Carolina
  • E. Osenbaugh

    • University of North Carolina
  • J. Clark

    • Yale University
  • C. Deibel

    • Yale University
  • A. Parikh

    • Yale University
  • P. Parker

    • Yale University
  • C. Wrede

    • Yale University