Reaction Rates for 146Sm Production in Supernovae
T. Rauscher, F.-K. Thielemann, H. Oberhummer;
    Ap. J. Lett. 451 (1995) L37.

Abstract:
Correlations of the $^{142}$Nd/$^{144}$Nd ratio with the Sm/Nd ratio in
some meteorites have been previously explained by the $\alpha$-decay of
long-lived  $^{146}$Sm. In order to account for these observations, a
necessary production ratio for $^{146}$Sm/$^{144}$Sm in the $\gamma$-process 
of 0.1--0.7 was deduced. The ratio 
($^{148}$Gd($\gamma$,n)$^{147}$Gd)/($^{148}$Gd($\gamma$,$\alpha$)$^{144}$Sm),
which plays the dominant role in the production of $^{146}$Sm/$^{144}$Sm, 
has been re-determined in the present paper by improved statistical model 
calculations. Utilization of folding potentials for the $\alpha$-channel reduce
the ($\gamma$,$\alpha$) rate by a factor of 3, which would enhance the 
production ratios, previously predicted at the lower limit of the allowed 
range 0.1--0.7. However, additional improvements in the treatment of nuclear 
level densities also reduce the ($\gamma$,n) rate by a factor of 0.4. Thus, 
in total the new cross section calculations result, at best, only in a modestly
enhanced production ratio of $^{146}$Sm/$^{144}$Sm.