The beta-delayed alpha-spectrum of N-16 and the astrophysical aspects of the C-12 alpha, gamma O-16 reaction

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Nitrogen 16, Alpha Particles, Carbon 12, Oxygen Isotopes, Astrophysics, Energy Spectra, Elastic Scattering, Helium, Matrices (Mathematics), Scattering Cross Sections, Isotope Separation, Particle Decay, Phase Shift, Massive Stars, Red Giant Stars, Beta Particles, Cosmochemistry

Scientific paper

Radiative alpha-capture by C-12 is a key process occurring during the helium-burning phase in red giant stars, and its rate remains one of the most significant uncertainties in the nucleo-synthetic calculations for massive stars. This is largely due to the lack of precise experimental information concerning the values of the reduced alpha-particle widths of the Jpi = 1(-) and 2(+) subthreshold states in O-16 to which the higher-energy radiative capture data are only weakly sensitive. Of these two states, the reduced alpha-width of the Ex = 7.12 MeV Jpi = 1(-) level has been predicted to have a considerable effect on the structure of the hitherto unmeasured low-energy region of the beta-delayed alpha-particle spectrum of N-16. Experiments using the TRIUMF isotope separator TISOL have been performed to measure this alpha-spectrum down to an energy of E-alpha = 600 keV, utilizing a coincidence technique which also accounts completely for the detector response function. The alpha-spectrum, containing 106 counts, has been incorporated into both R- and K-matrix analyses along with the previously measured C-12(alpha, gamma)O-16 cross section and the C-12 + alpha elastic phase shifts to yield a much improved value for SE1(300) keV. In light of this new determination of SE1(300), the available radiative capture data and elastic scattering phase shifts are reanalyzed, along with beta-delayed alpha-spectrum of N-16 in an attempt also to place improved limits on the SE1(300) contribution to the C-12(alpha, gamma)O-16 cross section.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The beta-delayed alpha-spectrum of N-16 and the astrophysical aspects of the C-12 alpha, gamma O-16 reaction does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The beta-delayed alpha-spectrum of N-16 and the astrophysical aspects of the C-12 alpha, gamma O-16 reaction, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The beta-delayed alpha-spectrum of N-16 and the astrophysical aspects of the C-12 alpha, gamma O-16 reaction will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1568531

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.