24 research outputs found
Mean first passage time for nuclear fission and the emission of light particles
The concept of a mean first passage time is used to study the time lapse over
which a fissioning system may emit light particles. The influence of the
"transient" and "saddle to scission times" on this emission are critically
examined. It is argued that within the limits of Kramers' picture of fission no
enhancement over that given by his rate formula need to be considered.Comment: 4 pages, RevTex, 4 postscript figures; with correction of misprints;
appeared in Phys. Rev. Lett.90.13270
Statistical fluctuations for the fission process on its decent from saddle to scission
We reconsider the importance of statistical fluctuations for fission dynamics
beyond the saddle in the light of recent evaluations of transport coefficients
for average motion. The size of these fluctuations are estimated by means of
the Kramers-Ingold solution for the inverted oscillator, which allows for an
inclusion of quantum effects.Comment: 12 pages, Latex, 5 Postscript figures; submitted to PRC e-mail:
[email protected] www home page:
http://www.physik.tu-muenchen.de/tumphy/e/T36/hofmann.htm
On nuclear transport at small excitations
Numerical computations of transport coefficients at low temperatures are
presented for shapes typically encountered in nuclear fission. The influence of
quantum effects of the nucleonic degrees of freedom is examined, with pair
correlations included. Consequences for global collective motion are studied
for the case of the decay rate. The range of temperatures is specified above
which this motion may be described as a quantal diffusion process.Comment: 8 pages, LaTex, 2 postscript figures; final version with small
editorial changes, Phys. Rev. Lett. 82 (1999) 4603; e-mail:
[email protected]; [email protected]
Ueber die Dynamik statistischer Fluktuationen bei der Kernspaltung
With 59 refs.SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
Incomplete linear momentum transfer in nuclear reactions: An interplay between one-body and two-body dissipation
An explanation for the experimentally observed linear momentum transfer in light- and heavy-ion induced reactions is propounded by simple geometrical considerations in momentum space. We display explicity the transition from one-body to two-body dissipation. We obtain a surprising agreement with the experiments over the whole measured energy range
Dynamical decay of nuclei at high temperature: competition between particle emission and fission decay
A generalized diffusion equation is propounded to follow the time evolution of an excited nucleus towards fission including along the particle decay. This theoretical model is built in order to try to analyse the anomalous behaviour of particle emission observed in many experimental data for heavy-ion induced reactions. Some calculations for the systems194Hg,170Yb and248Cf are presented. A possible extension of this generalized formalism is suggested to deal more consistently with the experimental data