Conveners
Fission
- Toshihiko Kawano
Fission
- Patrick Talou (Los Alamos National Laboratory, USA)
The experimental yields of fragment mass and charge distributions for the neutron-induced fission of 30 actinide nuclei are well described in the model [1,2], which considers the fissioning scission system consisting of two heavy fragments and α-particle between them. The α-particle has its origin in the neck nucleons. The yield of fission fragments in the model is linked to the number of...
Anton P. Tonchev1,4, Anthony P.D. Ramirez1, Ron C. Malone1, Jack A. Silano1, Roger Henderson1, Mark A. Stoyer1, Nicolas Schunck1, Matthew E. Gooden2, Jerry Wilhelmy2, Werner Tornow3,4, Calvin R. Howell3,4,Sean Finch3,4
1 Lawrence Livermore National Laboratory, Livermore, California 94550, USA
2 Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
3 Triangle...
Despite the recent experimental and theoretical progress in the investigation of the nuclear fission process, a complete description still represents a challenge in nuclear physics because it is a very complex dynamical process, whose description involves the coupling between intrinsic and collective degrees of freedom as well as different quantum-mechanical phenomena. Due to this complexity...
We present the fission fragment decay calculation results by the nuclear reaction model code, TALYS, that adopts the Hauser-Feshbach statistical decay theory to the de-excitation of fission fragments evaporating by emitting neutron and $\gamma$. TALYS incorporates so-called "Fission Fragment Database" which consists of yield $Y$, charge $Z$, mass $A$, excitation energy $E_x$, spin $J$, and...
The fast proton-induced fission cross-sections of 238U have been analyzed from the threshold up to 70 MeV. Calculations were performed on fission variables such as cross-sections, mass distributions, and prompt neutron emission. For the analysis, Talys and programs written by authors were used to describe the fission process using a Brosa model. As a result, we estimate the contribution of...
Isomeric states have been observed in about 150 of the hundreds of isotopes that can be produced in the fission of major actinides. These isomers can be populated directly through fission, and the isomeric yield ratio (IYR) represents the relative population of the excited state(s) and the ground state (GS) independent yield.
Due to the underlying nuclear structure, the isomeric state often...
While nuclear fission has been extensively studied for over 80 years, this phenomenon still lacks a complete and fully microscopic description. One of its most intriguing properties are the spin distributions of the fission fragments (FFs), quantities that are not directly observable in experiment yet play an important role in determining the properties of the neutrons and gammas emitted from...
Electron and gamma ray spectra from the neutron induced fission of 235U, 239,241Pu were measured at ORNL in the 1970s by J.K. Dickens and collaborators. These spectra were used to derive some of the most accurate electron and gamma decay heat values to be used in simulations of Loss Of Coolant Accidents (LOCA) scenarios. These spectra, however, have only been published in ORNL reports, and are...
