PUBLISHED IN: Physical Review Letters 106 132503 (2011)
(LANL PREPRINT LA-UR-10-06451)

Brownian Shape Motion on Five-Dimensional Potential-Energy Surfaces: Nuclear Fission-Fragment Mass Distributions



J. RANDRUP
Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA,

P. MÖLLER
Theoretical Division, Los Alamos National Laboratory, Los Alamos,
New Mexico 87545, USA

Although nuclear fission can be understood qualitatively as an evolution of the nuclear shape, a quantitative description has proven to be very elusive. In particular, until now, there existed no model with demonstrated predictive power for the fission-fragment mass yields. Exploiting the expected strongly damped character of nuclear dynamics, we treat the nuclear shape evolution in analogy with Brownian motion and perform random walks on five-dimensional fission potential-energy surfaces which were calculated previously and are the most comprehensive available. Test applications give good reproduction of highly variable experimental mass yields. This novel general approach requires only a single new global parameter, namely, the critical neck size at which the mass split is frozen in, and the results are remarkably insensitive to its specific value.

The complete manuscript as a .pdf file is also available for download.

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Figure 1 (ps.gz) or Figure 1 (.pdf) are available for download.


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Created: Dec 07 2011 --> Last modified: Thu July 5 2012