Mass distributions in monoenergetic-neutron-induced fission of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Pu</mml:mi></mml:mrow><mml:mprescripts /><mml:mrow /><mml:mrow><mml:mn>239</mml:mn></mml:mrow><mml:mrow /><mml:mrow /></mml:mmultiscripts></mml:mrow></mml:math>

Gindler, J.E.; Glendenin, L.E.; Henderson, D. J.; Meadows, J.W.

doi:10.1103/physrevc.27.2058

Cited by 31 publications

(28 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have not assumed that E 1 and E 2 are identical for U and Pu, because the transition from asymmetric to more symmetric fission is not as smooth a function of energy in the few-MeV region for Pu as it is for U [20,21]. We take N 0 1 = 0.757 and N 0 2 = 0.242.…”

Section: B Mass and Charge Partitionmentioning

confidence: 99%

“…While no such data are yet available for Pu, there exist more detailed data for 235 U(n, f ) that give the fragment yields as functions of both mass and total kinetic energy, Y (A f , TKE) for E n ≤ 6 MeV [19]. Guided by the energy dependence of these data, together with other available data on the product yields from 235 U(n, f ) [20] and 239 Pu(n, f ) [21] we derive an approximate energy dependence of the fragment yields for 239 Pu(n, f ) up to E n = 20 MeV.…”

Section: B Mass and Charge Partitionmentioning

confidence: 99%

See 1 more Smart Citation

Event-by-event evaluation of the prompt fission neutron spectrum from239Pu(n,f)

et al. 2012

View full text Add to dashboard Cite

Section: B Mass and Charge Partitionmentioning

confidence: 99%

Section: B Mass and Charge Partitionmentioning

confidence: 99%

Event-by-event evaluation of the prompt fission neutron spectrum from239Pu(n,f)

et al. 2012

View full text Add to dashboard Cite

“…According to Tables XI and XII, the calculated proba- [194][195][196][197] are compared with the result of the GEF code.…”

Section: Andmentioning

confidence: 99%

General Description of Fission Observables: GEF Model Code

Schmidt

Jurado

Amouroux

et al. 2016

Nuclear Data Sheets

426

421

View full text Add to dashboard Cite

The GEF ("GEneral description of Fission observables") model code is documented. It describes the observables for spontaneous fission, neutron-induced fission and, more generally, for fission of a compound nucleus from any other entrance channel, with given excitation energy and angular momentum. The GEF model is applicable for a wide range of isotopes from Z = 80 to Z = 112 and beyond, up to excitation energies of about 100 MeV. The results of the GEF model are compared with fission barriers, fission probabilities, fission-fragment mass-and nuclide distributions, isomeric ratios, total kinetic energies, and prompt-neutron and prompt-gamma yields and energy spectra from neutron-induced and spontaneous fission. Derived properties of delayed neutrons and decay heat are also considered.The GEF model is based on a general approach to nuclear fission that explains a great part of the complex appearance of fission observables on the basis of fundamental laws of physics and general properties of microscopic systems and mathematical objects. The topographic theorem is used to estimate the fission-barrier heights from theoretical macroscopic saddle-point and ground-state masses and experimental ground-state masses. Motivated by the theoretically predicted early localisation of nucleonic wave functions in a necked-in shape, the properties of the relevant fragment shells are extracted. These are used to determine the depths and the widths of the fission valleys corresponding to the different fission channels and to describe the fission-fragment distributions and deformations at scission by a statistical approach. A modified composite nuclear-level-density formula is proposed. It respects some features in the superfluid regime that are in accordance with new experimental findings and with theoretical expectations. These are a constant-temperature behaviour that is consistent with a considerably increased heat capacity and an increased pairing condensation energy that is consistent with the collective enhancement of the level density. The exchange of excitation energy and nucleons between the nascent fragments on the way from saddle to scission is estimated according to statistical mechanics. As a result, excitation energy and unpaired nucleons are predominantly transferred to the heavy fragment in the superfluid regime. This description reproduces some rather peculiar observed features of the prompt-neutron multiplicities and of the even-odd effect in fission-fragment Z distributions. For completeness, some conventional descriptions are used for calculating pre-equilibrium emission, fission probabilities and statistical emission of neutrons and gamma radiation from the excited fragments. Preference is given to simple models that can also be applied to exotic nuclei compared to more sophisticated models that need precise empirical input of nuclear properties, e.g. spectroscopic information.The approach reveals a high degree of regularity and provides a considerable insight into the physics of the fission process. Fission obs...

show abstract

“…The squares show various experimental data from Refs. [23] (A), [22] (B), [22] (C), and [24] (D); the charge yield from Ref. [23] have been multiplied by Z/A.…”

Section: Energy Dependence Of Yieldsmentioning

confidence: 99%

Nuclear shape evolution based on microscopic level densities

Ward

Carlsson

Døssing³

et al. 2017

Phys. Rev. C

View full text Add to dashboard Cite

By combining microscopically calculated level densities with the Metropolis walk method, we develop a consistent framework for treating the energy and angular-momentum dependence of the nuclear shape evolution in the fission process. For each nucleus under consideration, the level density is calculated microscopically for each of more than five million shapes with a recently developed combinatorial method. The method employs the same single-particle levels as those used for the extraction of the pairing and shell contributions to the macroscopic-microscopic deformation-energy surface. Containing no new parameters, the treatment is suitable for elucidating the energy dependence of the dynamics of warm nuclei on pairing and shell effects. It is illustrated for the fission fragment mass distribution for several uranium and plutonium isotopes of particular interest.

show abstract

Mass distributions in monoenergetic-neutron-induced fission ofPu239

Cited by 31 publications

References 7 publications

Event-by-event evaluation of the prompt fission neutron spectrum from239Pu(n,f)

Event-by-event evaluation of the prompt fission neutron spectrum from239Pu(n,f)

General Description of Fission Observables: GEF Model Code

Nuclear shape evolution based on microscopic level densities

Contact Info

Product

Resources

About