Possible Angular Momentum Dependence of Dissipation in Nuclear Fission
Abstract
A comparative analysis of the pre-scission neutron multiplicities observed in a new experiment [1] and one reported earlier [2] suggests that, besides known deformation [3] and temperature [4] dependencies, nuclear dissipation in fission may have an angular momentum dependence. The analysis based on a Langevin equation coupled with a statistical decay model [3] considers angular momentum effects on fission dynamics. Pre-saddle reduced dissipation coefficients of β = 2 x10^21s-1 and 3 x10^21s-1 have been extracted for the matched reactions ^16O + ^181Ta and ^19F + ^178Hf [1],respectively. The difference in the extracted β values is attributed to the difference in the angular momenta contributing to the fission process in the two reactions. Work attempting to derive a quantitative expression for an angular momentum dependence of the dissipation strength is in progress. [1] H.Singh et al., Phys. Rev. C76 (2007) 044610 [2] L.G.Moretto et al., Phys. Rev. Lett. 75 (1995) 4186; Phys. Rev. C54 (1996) 3062 [3] P.Frobrich and I.I.Gontchar, Phys. Rep. 292(1998) 131 [4] P.Paul and M.Thoennessen, Ann. Rev. Part. Sci. 44(1994) 65
- Publication:
-
APS April Meeting Abstracts
- Pub Date:
- April 2008
- Bibcode:
- 2008APS..APRE14004Y