Decay time of heavy excited nuclei

Drozdov, V. A.; Eremenko, D. O.; Fotina, O. V.; Giardina, G.; Malaguti, F.; Platonov, S. Yu.; Yuminov, O. A.

doi:10.1016/j.nuclphysa.2004.01.040

Cited by 9 publications

(4 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many investigations of the relaxation time in fusion-fission and quasifission reactions [20,22,52,61,62,[97][98][99][100][101][102] predict a value of τ K ranging from ∼10 −21 s to ∼10 −20 s depending on the spin, transition-state deformation, and type of the investigated reaction. The γ K and I influence τ K in a different way.…”

Section: The Angular Distribution Of Fission Fragmentsmentioning

confidence: 99%

Four-dimensional Langevin dynamics of heavy-ion-induced fission

et al. 2012

View full text Add to dashboard Cite

A four-dimensional dynamical model based on Langevin equations was developed and applied to calculate a wide set of experimental observables for the reactions 16 O + 208 Pb → 224 Th and 16 O + 232 Th → 248 Cf over a wide range of excitation energy. The fusion-fission and evaporation residue cross sections, fission fragment mass-energy distribution parameters, prescission neutron multiplicities, and anisotropy of angular distribution of fission fragments could be reasonably reproduced using a modified one-body mechanism for nuclear friction with a reduction coefficient of the contribution from a wall formula k s 0.25 and a dissipation coefficient for the orientation degree of freedom (K coordinate) γ K 0.077 (MeV zs) −1/2 . Inclusion of the K coordinate into calculation of potential energy changes the stiffness of the nucleus with respect to mass asymmetry coordinate for the values of K = 0 and results in a shift of the Businaro-Gallone point towards larger Z 2 /A values. The experimental data on the fission fragment mass-energy distribution parameters together with mean prescission neutron multiplicity for heavy fissioning nuclei are reproduced through the four-dimensional Langevin calculations more accurately than through three-dimensional calculations.

show abstract

Section: The Angular Distribution Of Fission Fragmentsmentioning

confidence: 99%

Four-dimensional Langevin dynamics of heavy-ion-induced fission

et al. 2012

View full text Add to dashboard Cite

show abstract

“…The dynamical model of the calculation of the fission fragment angular distributions proposed in [32,33] was generalized here to the case of three-dimensional Langevin model. In the present model, the fission dynamics described within the Langevin approach by the three collective coordinates determining the shape of the compound nucleus (c, h, α ) [9][10][11][12] was joined with the stochastic dynamics of the tilting mode.…”

Section: Formalism Of Calculation Of Fission Fragment Angular Distribmentioning

confidence: 99%

“…However, the dynamical aspects of the angular distribution formation can be contained within a characteristic named the tilting mode relaxation time τ K . In [32], it was proposed that the evolution of the tilting mode be considered using the Monte Carlo method. In [32], the fission process was characterized by two collective degrees of freedom: the elongation of the nucleus and K.…”

Section: Formalism Of Calculation Of Fission Fragment Angular Distrib...mentioning

confidence: 99%

See 1 more Smart Citation

Dynamical treatment of fission fragment angular distribution

Карпов

Hiryanov

Sagdeev

et al. 2006

J. Phys. G: Nucl. Part. Phys.

View full text Add to dashboard Cite

A dynamical approach to the treatment of fission fragment angular distribution is developed. The approach is based on three-dimensional Langevin dynamics for shape collective coordinates joined with the Monte Carlo algorithm for the degree of freedom associated with the projection K of the total angular momentum of the fissioning system on the symmetry axis. The relaxation time of the tilting mode τ K is estimated. From fits to experimental data on the fission fragment angular distribution of heavy fissioning compound systems, the K equilibration time is deduced to be ∼4 × 10 −21 s for temperatures ∼1-2 MeV. A modified one-body mechanism of nuclear viscosity with the reduction coefficient of the contribution from the 'wall' formula k s = 0.25 has been used in calculations.

show abstract