Recoil studies of some light-mass products from the proton-induced fission of 238U at intermediate energies

1969 ◽  
Vol 47 (4) ◽  
pp. 655-662 ◽  
Author(s):  
G. B. Saha ◽  
L. Yaffe
Keyword(s):  
Kinetic Energy ◽  
Energy Region ◽  
Fission Products ◽  
Thick Target ◽  
Average Kinetic Energy ◽  
Intermediate Energies ◽  
Energy Relationships ◽  
Kinetic Release ◽  
Induced Fission ◽  
Bombarding Energy

The recoil properties of 66Ni, 67Cu, and 72Zn produced in the fission of 238U by protons of 40–85 MeV energy have been studied radiochemically by the thick target – thick catcher technique. The average kinetic energy of each product has been calculated from the ranges by use of known range–energy relationships. The calculated impact velocity vll shows that these fission products are formed predominantly via a compound nucleus mechanism in this energy region. The average total kinetic release in fission is found to be insensitive to the bombarding energy.

A CALORIMETRIC DETERMINATION OF THE AVERAGE KINETIC ENERGY OF THE FRAGMENTS FROM U235 FISSION

1955 ◽  
Vol 33 (7) ◽  
pp. 357-363 ◽  
Author(s):  
R. B. Leachman ◽  
W. D. Schafer
Keyword(s):  
Kinetic Energy ◽  
Average Energy ◽  
Fission Products ◽  
Average Kinetic Energy ◽  
U235 Fission ◽  
Induced Fission ◽  
Differential Calorimeter ◽  
Calorimetric Determination ◽  
Good Agreement

The average heat of thermal-neutron induced fission of U235 has been measured by a differential calorimeter. The average energy per fission observed by the calorimeter was 170.1 ± 1.2 Mev. On the basis of the thicknesses of the calorimeter materials and the theoretical energy loss equation, the β energy per fission observed by the calorimeter is 3.0 ± 1 Mev. and, on the same basis, the γ and neutron energy observed is negligible. The resulting 167.1 ± 1.6 Mev. for the average kinetic energy of the fission products is shown to be in good agreement with less direct determinations of this quantity.

scholarly journals The γ-γ fast-timing technique and the EXILL&FATIMA campaign

2018 ◽  
Vol 193 ◽  
pp. 04008
Author(s):  
J.-M. Régis ◽  
G.S. Simpson ◽  
H. Mach ◽  
A. Blanc ◽  
M. Jentschel ◽  
...  
Keyword(s):  
Fission Products ◽  
Thick Target ◽  
Difference Spectra ◽  
Fast Timing ◽  
Time Correction ◽  
Γ Rays ◽  
Induced Fission ◽  
Energy Dependent ◽  
Timing Behaviour ◽  
Compton Background

At the Institut Laue-Langevin in Grenoble, germanium-gated γ-γ fast-timing lifetime measurements of nuclear excited states in neutron-rich nuclei have been performed within a prompt γ-ray spectroscopy experimental campaign. We report on results obtained from the cold-neutron induced fission of 235U. The excited secondary fission products were stopped almost instantaneously within the thick target and the γ rays emitted were collected triggerlessly using the EXILL&FATIMA mixed array of HPGe and LaBr3(Ce) detectors. Precise lifetimes could be determined by analysing the γ-γ time difference spectra using the generalized centroid difference method. This picosecondsensitive method provides many advantages and is briefly explained. Still, the major source of systematic errors is related to the contribution of time-correlated Compton background. The EXILL&FATIMA results are discussed with respect to the typical energy-dependent timing behaviour of the background. According to the time response of the background, appropriate methods and a time correction for the sub-nanosecond regime are proposed.

scholarly journals From fission yield measurements to evaluation: status on statistical methodology for the covariance question

2018 ◽  
Vol 4 ◽  
pp. 26 ◽  
Author(s):  
Brieuc Voirin ◽  
Grégoire Kessedjian ◽  
Abdelaziz Chebboubi ◽  
Sylvain Julien-Laferrière ◽  
Olivier Serot
Keyword(s):  
Statistical Tests ◽  
Fission Products ◽  
Experimental Program ◽  
Mass Yield ◽  
Statistical Methodology ◽  
Fission Yield ◽  
Fission Process ◽  
Induced Fission ◽  
Entropy Criterion ◽  
Fission Yields

Studies on fission yields have a major impact on the characterization and the understanding of the fission process and are mandatory for reactor applications. Fission yield evaluation represents the synthesis of experimental and theoretical knowledge to perform the best estimation of mass, isotopic and isomeric yields. Today, the output of fission yield evaluation is available as a function of isotopic yields. Without the explicitness of evaluation covariance data, mass yield uncertainties are greater than those of isotopic yields. This is in contradiction with experimental knowledge where the abundance of mass yield measurements is dominant. These last years, different covariance matrices have been suggested but the experimental part of those are neglected. The collaboration between the LPSC Grenoble and the CEA Cadarache starts a new program in the field of the evaluation of fission products in addition to the current experimental program at Institut Laue-Langevin. The goal is to define a new methodology of evaluation based on statistical tests to define the different experimental sets in agreement, giving different solutions for different analysis choices. This study deals with the thermal neutron induced fission of 235U. The mix of data is non-unique and this topic will be discussed using the Shannon entropy criterion in the framework of the statistical methodology proposed.

Rainfall intensity–kinetic energy relationships: a critical literature appraisal

2002 ◽  
Vol 261 (1-4) ◽  
pp. 1-23 ◽  
Author(s):  
A.I.J.M van Dijk ◽  
L.A Bruijnzeel ◽  
C.J Rosewell
Keyword(s):  
Kinetic Energy ◽  
Rainfall Intensity ◽  
Energy Relationships ◽  
Critical Literature

The interaction of atomic particles with solid surfaces at intermediate energies IV. The energy and angular distributions of particles scattered with electric charge from polycrystalline platinum at bombarding energies of 500-5000 eV

1974 ◽  
Vol 341 (1625) ◽  
pp. 213-231 ◽  
Keyword(s):  
Charged Particles ◽  
Solid Surfaces ◽  
Hydrogen Ion ◽  
Angular Distributions ◽  
Sodium Potassium ◽  
Intermediate Energies ◽  
Polycrystalline Platinum ◽  
Composite Spectra ◽  
Energy And Angular Distributions ◽  
Bombarding Energy

The distributions in angle and energy for charged particles emitted from polycrystalline platinum bombarded with ions of hydrogen, sodium, potassium and some hydrocarbons, have been measured, in continuation of previous work (Cawthron, Cotterell & Oliphant 1969 a , b , parts I and II; 1970, part III) to lower energies. Composite spectra are presented, including ions of both signs. The flux of emitted charged particles, under hydrogen ion bombardment, is shown to contain approximately equal numbers of protons and H¯ ions, except at the lowest bombarding energies, where the latter apparently predominate. Scattering in all cases is shown to increase with bombarding energy over the range covered, the increase being near linear for hydrogen and very rapid for alkalimetal ions. In all cases the total emission of charged particles is very small at the lowest bombarding energies employed.

BIMODAL FISSION IN 258FM

1986 ◽  
Vol 01 (06) ◽  
pp. 377-381 ◽  
Author(s):  
K. DEPTA ◽  
J.A. MARUHN ◽  
W. GREINER ◽  
W. SCHEID ◽  
A. SANDULESCU
Keyword(s):  
Kinetic Energy ◽  
Shell Model ◽  
Fission Products ◽  
Degree Of Freedom ◽  
Total Kinetic Energy ◽  
Heavy Nuclei ◽  
Energy Distributions ◽  
Decay Channels ◽  
Symmetric Fission ◽  
Kinetic Energy Distributions

Within the 2-center shell model we present an explanation for the mass and total-kinetic-energy distributions of fission products of very heavy nuclei called “bimodal fission.” For the case of 258 FM we show that the symmetric fission can be described by a 2-dimensional treatment of the elongation and neck degree of freedom. Owing to shell corrections the system fissions via two decay channels that have distinct kinetic energies.

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