scholarly journals Dynamical Modeling of the Nuclear Fission Process at Low Excitation Energies

2014 ◽  
Vol 02 (05) ◽  
pp. 27-31
Author(s):  
I. I. Gontchar ◽  
M. V. Chushnyakova ◽  
E. P. Oskin ◽  
E. G. Demina
2020 ◽  
Vol 232 ◽  
pp. 03002
Author(s):  
Birger B. Back

Since its discovery in 1939, the nuclear fission process has provided much insight into the behavior of nuclei under many different conditions. As part of the nuclear chain reaction, the fission process has had a profound impact on modern society and it has consequently attracted much attention to the field of nuclear physics. In this talk, I will argue that the time is ripe for a resumption of studies of the fission process induced by light charged particle reactions. Although fission can be induced in heavy nuclei by several means, in some cases these methods suffer from the complication that fission can occur at several points during the decay chain thus mixing up contributions from different excitation energies. Using instead light charged particle reactions to excite the nuclei in question, the precise excitation energy from which fission takes place, can be determined. In fact, a number of such studies were carried out previously, and a first set of results on fission barrier heights, mass, energy and angular distributions were obtained. Applying detection techniques developed over the last decades will allow researchers to obtain detailed, high-quality data from which to probe and refine our present understanding of the process. Based on these observations, I suggest that substantial advances in the study of this process can be achieved by using simple light charged particle reactions.


2020 ◽  
Vol 242 ◽  
pp. 03005
Author(s):  
M. Verriere ◽  
M.R. Mumpower ◽  
T. Kawano ◽  
N. Schunck

Nuclear fission is the splitting of a heavy nucleus into two or more fragments, a process that releases a substantial amount of energy. It is ubiquitous in modern applications, critical for national security, energy generation and reactor safeguards. Fission also plays an important role in understanding the astrophysical formation of elements in the universe. Eighty years after the discovery of the fission process, its theoretical understanding from first principles remains a great challenge. In this paper, we present promising new approaches to make more accurate predictions of fission observables.


2018 ◽  
Vol 169 ◽  
pp. 00024 ◽  
Author(s):  
F. Tovesson ◽  
D. Duke ◽  
V. Geppert-Kleinrath ◽  
B. Manning ◽  
D. Mayorov ◽  
...  

Different aspects of the nuclear fission process have been studied at Los Alamos Neutron Science Center (LANSCE) using various instruments and experimental techniques. Properties of the fragments emitted in fission have been investigated using Frisch-grid ionization chambers, a Time Projection Chamber (TPC), and the SPIDER instrument which employs the 2v-2E method. These instruments and experimental techniques have been used to determine fission product mass yields, the energy dependent total kinetic energy (TKE) release, and anisotropy in neutron-induced fission of U-235, U-238 and Pu-239.


2009 ◽  
Vol 18 (04) ◽  
pp. 767-772 ◽  
Author(s):  
J. TAIEB ◽  
G. BELIER ◽  
A. CHATILLON ◽  
T. GRANIER ◽  
A. KELIC ◽  
...  

A novel experimental program aiming to study the properties of fragments and neutrons emitted in the fission process has been initiated. The experiment will be held at the ELISe electron-ion collider to be constructed at GSI, Darmstadt in the framework of the FAIR extension of the facility. The experiment will take advantage of the inverse kinematics allowing, in particular, a total mass and charge resolution for all fission fragments.


2020 ◽  
Vol 242 ◽  
pp. 01008
Author(s):  
Jack Silano ◽  
Anton Tonchev ◽  
Roger Henderson ◽  
Nicolas Schunck ◽  
Werner Tornow ◽  
...  

Fission product yields (FPYs) are a uniquely sensitive probe of the fission process, with well established dependence on the species of nucleus undergoing fission, its excitation energy and spin. Thus FPYs are well suited for testing Bohr’s hypothesis in the context of nuclear fission, which states that the decay of a compound nucleus with a given excitation energy, spin and parity is independent of its formation. Using FPYs, we have performed a new highprecision test of the combined effects of the entrance channel, spin and parity on the fission process from two of the most commonly used particles to induce fission neutrons and photons. The 239 Pu(n,f) reaction at En = 4.6 MeV and the 240 Pu(γ,f) reaction at Eγ = 11.2 MeV were used to produce a 240 Pu∗ compound nucleus with the same excitation energy. The FPYs from these two reactions were measured using quasimonoenergetic neutron beams from the TUNL’s FN tandem Van de Graaff accelerator and quasimonenergetic photon beams from the High Intensity γ-ray Source (HIγS) facility. The FPYs from these two reactions are compared quantitatively for the first time.


Author(s):  
Remond R. Pahladsingh

During the fission process in most of the presently operating nuclear reactors nuclear energy is converted into thermal energy and transferred to common steamcycles for powergeneration. As part of the fission process also α-, β- and neutrons particles are released from the nucleus; the release of gamma-rays is also a part of the fission process. In present nuclear reactors α-, β-, neutrons particles and particularly Gamma-rays are not gainfully used as a result of the reactor design and of the containment. These plants are built as required by regulations and international standards for safety. The inherently safe HTR reactor, by its physics and design, does not need a special reinforced containment and it is worth looking into the possibilities of this design feature to use the by-products, such as Gamma-rays, from nuclear fission. In the HTR Pebble Bed Reactors the α-, and β-particles will remain in the kernels in the pebbles. This means that only the neutron particles and gamma-rays will be available outside the reactor pressure vessel. In this report a proposal is presented to use the gamma-rays of the HTR reactor for irradiation of food and agricultural produce. For neutron shielding a reflector is placed inside the reactor while outside the reactor neutron- and thermal-shielding will be accomplished with water. The high energy gamma-rays will pass through the water-shield and could be harnessed for radiation processing of food and medical products.


2021 ◽  
Vol 30 (07) ◽  
pp. 2150065
Author(s):  
Mukhtar Ahmed Rana ◽  
Awais Ahmed ◽  
Farzana Siddique ◽  
Junaid Ahmed

A data bank of negative and positive (80–1665[Formula: see text]MeV) pion-induced experimental fission cross-sections of heavy nuclei from 119Sn to 238U is compiled using present results and published data from the literature. Corresponding calculations of fission cross-sections, using the cascade exciton model (CEM) are also included in the compilation. Fission cross-sections compiled in the data bank are examined critically. Mass and energy dependences of fission cross-sections are analyzed. Fission cross-sections of 238U targets are the highest and scale down approximately, for other targets studied, with fissility, [Formula: see text]. In the fissility expression, [Formula: see text] and [Formula: see text] are atomic and mass numbers of the target while [Formula: see text] refer to positive and negative pion projectiles. The presented data bank is of interest for students and researchers involved in the investigation of energetic light particle-induced fission of heavy nuclei. Nuclear fission of heavy nuclei has been classified into three regimes. Phenomenological discussion of the fission process is also given.


2010 ◽  
Vol 8 ◽  
pp. 07011
Author(s):  
Y. Ayyad ◽  
J. Benlliure ◽  
E. Casarejos ◽  
H. Álvarez Pol ◽  
A. Bacquias ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document