scholarly journals Macroscopic-microscopic approach to the nuclear fission process

2007 ◽  
Author(s):  
Aleksandra Kelić ◽  
Maria Valentina Ricciardi ◽  
Karl-Heinz Schmidt
Keyword(s):  
Nuclear Fission ◽  
Microscopic Approach ◽  
Fission Process

scholarly journals Improvements to the macroscopic-microscopic approach of nuclear fission

2021 ◽  
Vol 103 (3) ◽  
Author(s):  
Marc Verriere ◽  
Matthew Ryan Mumpower
Keyword(s):  
Nuclear Fission ◽  
Microscopic Approach

scholarly journals Description of the Fission Process: Nuclear Models for Fission Dynamics

2020 ◽  
Vol 242 ◽  
pp. 03005
Author(s):  
M. Verriere ◽  
M.R. Mumpower ◽  
T. Kawano ◽  
N. Schunck
Keyword(s):  
National Security ◽  
Heavy Nucleus ◽  
First Principles ◽  
Energy Generation ◽  
Nuclear Fission ◽  
Theoretical Understanding ◽  
Fission Process ◽  
New Approaches ◽  
Nuclear Models ◽  
The Universe

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.

scholarly journals Fission fragment yields and total kinetic energy release in neutron-induced fission of235,238U,and239Pu

2018 ◽  
Vol 169 ◽  
pp. 00024 ◽  
Author(s):  
F. Tovesson ◽  
D. Duke ◽  
V. Geppert-Kleinrath ◽  
B. Manning ◽  
D. Mayorov ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Kinetic Energy Release ◽  
Nuclear Fission ◽  
Total Kinetic Energy ◽  
Experimental Techniques ◽  
Science Center ◽  
Fission Process ◽  
Induced Fission ◽  
Time Projection ◽  
Energy Dependent

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.

ELISe: A NEW FACILITY FOR UNPRECEDENTED EXPERIMENTAL NUCLEAR FISSION STUDIES

2009 ◽  
Vol 18 (04) ◽  
pp. 767-772 ◽  
Author(s):  
J. TAIEB ◽  
G. BELIER ◽  
A. CHATILLON ◽  
T. GRANIER ◽  
A. KELIC ◽  
...  
Keyword(s):  
Inverse Kinematics ◽  
Total Mass ◽  
Nuclear Fission ◽  
Experimental Program ◽  
Fission Process ◽  
Fission Fragments ◽  
Charge Resolution ◽  
New Facility

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.

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
Keyword(s):  
Nuclear Fission ◽  
Excitation Energies ◽  
Dynamical Modeling ◽  
Fission Process

scholarly journals Comparing fission-product yields from photon-induced fission of 240Pu and neutron-induced fission of 239Pu as a test of the Bohr hypothesis in nuclear fission

2020 ◽  
Vol 242 ◽  
pp. 01008
Author(s):  
Jack Silano ◽  
Anton Tonchev ◽  
Roger Henderson ◽  
Nicolas Schunck ◽  
Werner Tornow ◽  
...  
Keyword(s):  
Fission Product ◽  
Excitation Energy ◽  
Compound Nucleus ◽  
Nuclear Fission ◽  
Photon Beams ◽  
Fission Process ◽  
Product Yields ◽  
Fission Product Yields ◽  
Induced Fission ◽  
First Time

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.

Possibility of Using Gamma Radiation From HTR Reactors for Processing of Food and Medical Products

2004 ◽  
Author(s):  
Remond R. Pahladsingh
Keyword(s):  
Gamma Rays ◽  
Nuclear Reactors ◽  
Design Feature ◽  
Nuclear Fission ◽  
High Energy ◽  
International Standards ◽  
Radiation Processing ◽  
Neutron Shielding ◽  
Fission Process ◽  
Medical Products

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.

Cascade exciton model analysis of energetic pion-induced fission of heavy nuclei: Target mass and projectile energy dependence

2021 ◽  
Vol 30 (07) ◽  
pp. 2150065
Author(s):  
Mukhtar Ahmed Rana ◽  
Awais Ahmed ◽  
Farzana Siddique ◽  
Junaid Ahmed
Keyword(s):  
Cross Sections ◽  
Data Bank ◽  
Nuclear Fission ◽  
Projectile Energy ◽  
Published Data ◽  
Heavy Nuclei ◽  
Exciton Model ◽  
Fission Process ◽  
Scale Down ◽  
Induced Fission

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.

FISSION COLLECTIVE DYNAMICS IN A MICROSCOPIC FRAMEWORK

2006 ◽  
Vol 15 (02) ◽  
pp. 292-301 ◽  
Author(s):  
H. GOUTTE ◽  
J.-F. BERGER ◽  
D. GOGNY
Keyword(s):  
Time Dependent ◽  
Microscopic Approach ◽  
Fission Process ◽  
Collective Dynamics ◽  
Mixing Method ◽  
Configuration Mixing ◽  
The Hill

A time-dependent microscopic approach of the fission process based on the constrained HFB approach with the Gogny force and the Hill and Wheeler configuration mixing method is described. Recent results concerning fragment distributions (mass, kinetic and deformation energies) and other fragment observables in 238 U obtained with such an approach are presented and discussed.

scholarly journals Validating the Bohr hypothesis: Comparing fission-product yields from photon-induced fission of 240Pu and neutron-induced fission of Pu

2020 ◽  
Vol 239 ◽  
pp. 03004
Author(s):  
Jack Silano ◽  
Anton Tonchev ◽  
Roger Henderson ◽  
Nicolas Schunck ◽  
Werner Tornow ◽  
...  
Keyword(s):  
Fission Product ◽  
Excitation Energy ◽  
Nuclear Fission ◽  
Photon Beams ◽  
Fission Process ◽  
Product Yields ◽  
Fission Product Yields ◽  
Consistent Manner ◽  
First Results ◽  
Induced Fission

The Bohr hypothesis, one of the most fundamental assumptions in nuclear fission theory, states that the decay of a compound nucleus with a given excitation energy, spin and parity is independent of its formation. Using fission product yields (FPYs) as a sensitive probe, we have performed new high precision test of the combined effects of the entrance channel, spin and parity on the fission process. Two different reactions were used in a self-consistent manner to produce a compound 240Pu nucleus with the same excitation energy: neutron induced fission of 239Pu at En = 4.6 MeV and photon-induced fission of 240Pu at Eγ = 11.2 MeV. 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 (HlγS) facility. The first results comparing the FPYs from these two reactions will be presented. Implications for validating the Bohr hypothesis will be discussed.

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