[Triumf-seminars] TRIUMF Seminar today at 14:00

[postmaster at admin.triumf.ca]

Date/Time: Thu 2008-02-07 at 14:00

Location:  Auditorium          

Speaker:   Lothar Buchmann (TRIUMF)

Title:     Some remarks about the beta-delayed alpha decay of 16N

Abstract: The beta-delayed alpha-decay of 16N has been used to restrict the E1 fraction of the ground state gamma-transition in the astrophysically important 12C(alpha,gamma)16O reaction. A review of the published measurements is given, and GEANT4 simulations and  R-Matrix calculations are presented to further clarify the observed alpha spectra. A clear response-function, low-energy tail from the scattering of alpha-particles in the catcher foil is observed in these simulations for any foil thickness. The simulations show that the TRIUMF measurement and those performed at Yale and Mainz originate from the same underlying spectrum. The R-matrix calculations reveal, in addition, that the S_E1(300) factor is relatively insensitive to some details of the spectrum. The simulations show in general that the form (width) of the spectrum is very sensitive to the catcher foil thickness.
It is concluded that the TRIUMF measurement most likely represents the currently closest approximation to the true beta-delayed alpha-decay spectrum of 16N.

Stimulants available 15 minutes before the talk.

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