Nuclear Charge Dispersion in the Fission of 235U by Protons of Energy 20–85 MeV

1971 ◽  
Vol 49 (13) ◽  
pp. 2205-2216 ◽  
Author(s):  
G. B. Saha ◽  
I. Tomita ◽  
L. Yaffe
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Nuclear Charge ◽  
Fission Products ◽  
Mass Range ◽  
Dispersion Curves ◽  
Cross Section Data ◽  
Excitation Functions ◽  
Section Data ◽  
Good Agreement

Independent formation cross sections of 129Cs, 130Cs, 131Cs, 134Csm, 134Csm+g, 136Cs, 139Ce, and cumulative formation cross sections of 141Ce and 143Ce were obtained when 235U was caused to fission with protons of energies varying between 20 and 85 MeV. The energies at which the excitation functions reached their maxima were related to the neutron-to-proton ratio of the fission products. These were compared with other fissioning systems. Charge dispersion curves were obtained from the cross section data. The variation of (ZA − Zp) with energy, both in magnitude and in trend, agrees extremely well with predictions made by Saha and Yaffe for nuclides in this mass range. Calculations for Zp show that good agreement is obtained with the unchanged charge division hypothesis. An estimate has been made of the total number of neutrons emitted in fission at these energies.

scholarly journals Analysis of the fusion cross sections for 16,18,20O + 12C systems at low energies

2019 ◽  
Vol 97 (7) ◽  
pp. 803-807 ◽  
Author(s):  
G. Kocak
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Optical Model ◽  
Fusion Cross Section ◽  
Nucleon Nucleon ◽  
Cross Section Data ◽  
Section Data ◽  
Low Energies ◽  
Double Folding ◽  
Good Agreement

Fusion cross section data for the 16,18,20O + 12C systems at energies near and below the Coulomb barrier are studied within the framework of the optical model. To examine these reactions, the microscopic nucleon–nucleon double folding potentials for real and imaginary parts are found. To make a comprehensive analysis of the effect of neutron-rich systems, we used three different reactions from stable to unstable systems. The microscopic nucleon–nucleon double folding potentials show very good agreement for 16,18,20O + 12C systems with a very weak imaginary potential. Also, we have obtained better agreement by using fully microscopic nucleon–nucleon double folding potentials with the 20O + 12C system’s experimental data than in previous works, but especially at low energies we still have some problems reproducing the 20O + 12C system’s fusion cross section data.

scholarly journals Spatial Non-uniformity in Discharges in Low Pressure Helium and Neon

1987 ◽  
Vol 40 (3) ◽  
pp. 383 ◽  
Author(s):  
J Fletcher ◽  
PH Purdie
Keyword(s):  
Monte Carlo Simulation ◽  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Low Pressure ◽  
Photon Flux ◽  
Cross Section Data ◽  
Section Data ◽  
Neon Gas ◽  
Wavelength Distribution

Low current, low pressure, steady state Townsend discharges in helium and neon gas have been investigated using the photon flux technique. Such discharges have been found to exhibit spatial non-uniformity resulting in luminous layers throughout the discharge. The separation and structure of these layers has been investigated experimentally in both gases along with the wavelength distribution of the photon flux. A Monte Carlo simulation of the discharge in neon has been used to gain information on the cross sections necessary to describe these discharges. It is found that direct excitaton of ground state atoms to the resonance level of each gas is less than indicated by some published cross section data.

Calculation of Line Broadening Cross Sections for Level Crossing Experiments in Alkali-Rare Gas Systems

1974 ◽  
Vol 29 (4) ◽  
pp. 605-609
Author(s):  
B. Grosswendt
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Rare Gas ◽  
Atomic Interaction ◽  
Cross Section Data ◽  
Line Broadening ◽  
Crossing Experiments ◽  
Level Crossing ◽  
Section Data ◽  
Frame Work

Using a simple approximation for the theoretical atomic interaction constants cross section data for level crossing and Hanle-effect line broadening experiments in Rb, Mg+ and Ca+ rare gas systems could be derived. It is shown that in the Rb system the interaction C6R-6 is predominant and that the results are little influenced by dipole-quadrupole and repulsive interactions in the frame work of the Lindholm-Foley-Hindmarsh theory.

Dynamics of 16,18O-induced reactions using Ni, Ge and Mo targets

2016 ◽  
Vol 25 (11) ◽  
pp. 1650091 ◽  
Author(s):  
Rajni ◽  
Gurvinder Kaur ◽  
Manoj K. Sharma
Keyword(s):  
Cross Sections ◽  
Fusion Cross Section ◽  
Cluster Decay ◽  
Cross Section Data ◽  
Orientation Degree ◽  
Decay Modes ◽  
Section Data ◽  
Collective Clusterization ◽  
Good Agreement

Dynamical cluster decay model (DCM) based on the collective clusterization approach is employed to explore the dynamics of various even-mass Zr isotopes formed in [Formula: see text]O-induced reactions. In reference to the measured fusion cross-section data, various decay modes contributing towards [Formula: see text]Zr[Formula: see text] nuclei are investigated. Also, the role of deformations and orientation degree of freedom is analyzed by comparing results with spherical choice of fragmentation. In addition to this, the effect of entrance channel is explored for [Formula: see text]Zr[Formula: see text] and [Formula: see text]Kr[Formula: see text] nuclei formed in [Formula: see text]O and [Formula: see text]O-induced reactions. Besides this, the dynamics of relatively heavier mass Sn isotopes is exercised using [Formula: see text]O and [Formula: see text]O projectiles. The DCM calculated decay cross-sections find good agreement with available experimental data.

Triple differential cross sections for the ionization of helium by intermediate-energy electrons

1988 ◽  
Vol 66 (1) ◽  
pp. 82-85
Author(s):  
K. S. Baliyan ◽  
M. K. Srivastava
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Intermediate Energy ◽  
Incident Electron Energy ◽  
Cross Section Data ◽  
Satisfactory Description ◽  
Triple Differential Cross Section ◽  
Section Data ◽  
Better Than

The recent triple differential cross-section data of Jung for the ionization of helium in the coplanar asymmetric geometry at 250 eV incident electron energy is analyzed within the framework of the second Born (B2) and modified Glauber (MG) approximations. At this energy B2 and MG results, although better than those obtained by using the first Born and Glauber approximations, do not lead to a satisfactory description of the experimental data in all the kinematic situations considered here.

scholarly journals 14.8 MeV Neutron Activation Cross Section Measurements for Ge Isotopes

2009 ◽  
Vol 1 (2) ◽  
pp. 173-181 ◽  
Author(s):  
M. M. Haque ◽  
M. T. Islam ◽  
M. A. Hafiz ◽  
R. U. Miah ◽  
M. S. Uddin
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Gamma Ray ◽  
Reaction Cross ◽  
Activation Cross Section ◽  
Section Data ◽  
Gamma Ray Spectroscopy ◽  
24Na Reaction ◽  
The Cross ◽  
Good Agreement

The cross sections of Ge isotopes were measured with the activation method at 14.8 MeV neutron energy. The quasi-monoenergetic neutron beams were produced via the 3H(d,n)4He reaction at the 150 kV J-25 neutron generator of INST, AERE. The characteristics γ-lines of the product nuclei were measured with a closed end coaxial 17.5 cm2 high purity germanium (HPGe) detector gamma ray spectroscopy. The cross sections were determined with reference to the known 27Al(n,α)24Na reaction. Cross section data are presented for 72Ge(n,p)72Ga, 74Ge(n,α)71mZn and 76Ge(n,2n)75m+gGe reactions. The cross section values obtained for the above reactions were 24.78±1.75 mb, 1.69±0.11 mb and 860±50 mb, respectively. The results obtained were compared with the values reported in literature as well as theoretical calculation performed by the statistical code SINCROS-II. The experimental data were found fairly in good agreement with the calculated and literature data.  Keywords: Activation cross section; Neutron induced reaction; Gamma-ray spectroscopy; 14.8 MeV. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1532  

Projectile breakup effects in the fusion dynamics of 6,7Li +144,152Sm reactions around Coulomb barrier

2020 ◽  
Vol 29 (05) ◽  
pp. 2050029
Author(s):  
Manjeet Singh Gautam ◽  
Sukhvinder Duhan ◽  
Rishi Pal Chahal ◽  
Hitender Khatri ◽  
Suman B. Kuhar ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Coulomb Barrier ◽  
Incomplete Fusion ◽  
Complete Fusion ◽  
Cross Section Data ◽  
Suppression Factor ◽  
Model Calculations ◽  
Section Data ◽  
Breakup Channel

This work emphasized the role of the projectile breakup channel by studying the complete fusion (CF) and incomplete fusion (ICF) dynamics of [Formula: see text] reactions. The theoretical calculations for the chosen reactions have been done by opting for the coupled channel approach and the energy dependent Woods–Saxon potential (EDWSP) model. The below barrier fusion enhancements of the studied reactions are reasonably addressed by the outcomes of the adopted models, which in turn can be attributed to the couplings of nuclear structure degrees of freedom of the collision partners to their relative motion. In contrast, at above barrier energies, the CF cross-section data of the chosen reactions are found to be suppressed significantly when compared with the predictions made by using the present models. Interestingly, the fusion suppression factors of the given reactions can be minimized considerably with respect to the reported value when it is analyzed within the framework of the EDWSP model. For instance, in case of [Formula: see text] ([Formula: see text] reaction, the magnitude of fusion suppression factor is minimized up to 7% (13%) relative to the reported value whereas for [Formula: see text] ([Formula: see text] reaction, the fusion suppression factor is found to be less by 7% (8%) with reference to the reported value. Such suppression effects can be correlated with the low breakup threshold of alpha breakup channel associated with the loosely bound projectile. The projectiles being weakly bound systems split into two charged fragments and either of the breakup components is absorbed by the target resulting in the reduction of incoming flux going into fusion channel. The flux lost from the CF channel appears in the form of ICF yields. For [Formula: see text], total fusion (TF) cross-sections that are sum of CF and ICF cross-sections are also analyzed in conjunction with the EDWSP model and thus reasonably explained by the model calculations. In order to identify the ICF contribution, the ratio of ICF/TF cross-section data of [Formula: see text] reaction has been examined and thus properly addressed by using the EDWSP model. The presence of ICF component in TF cross-section clearly pointed out the breakup of projectile due to its loosely bound nature prior to the Coulomb barrier. Although ICF data of other systems are not available in the literature, a similar behavior is expected for ICF and TF data for [Formula: see text] and [Formula: see text] reactions.

UNDERSTANDING THE NATURE OF PROTON–AIR CROSS-SECTIONS AT VERY HIGH ENERGIES AND THE IMPLICATIONS

2001 ◽  
Vol 16 (37) ◽  
pp. 2387-2397 ◽  
Author(s):  
BHASKAR DE ◽  
S. BHATTACHARYYA ◽  
P. GUPTAROY
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Cross Section Data ◽  
Section Data ◽  
High Energies ◽  
Production Models ◽  
Simulation Based ◽  
Effective Role ◽  
Very High

The purpose of this paper is to focus on the possible effective role of two relatively less-known models in analyzing comprehensively the very up-to-date data on proton–air inelastic cross-sections at high and ultra high energies. The standard versions of all the familiar simulation-based multiparticle production models, which nowadays normally claim front-ranking positions, address on the contrary, only a small part of the cross-section data for a very limited or sectional range of energy values. Against this background, the relevance and impact of the present study have finally been highlighted.

Nuclear charge dispersion of light-mass fission products in the fission of 235U and 238U by medium-energy protons

1970 ◽  
Vol 48 (12) ◽  
pp. 1924-1933 ◽  
Author(s):  
A. H. Khan ◽  
G. B. Saha ◽  
L. Yaffe
Keyword(s):  
Nuclear Charge ◽  
Fission Products ◽  
Mass Region ◽  
Dispersion Curves ◽  
Medium Energy ◽  
Excitation Functions ◽  
Charge Displacement ◽  
Fission Yields ◽  
Dispersion Of Light

Independent fission yields for 90Ym, 90Ym+g, 91Ym, 91Ym+g, and 92Y and cumulative yields for 91Sr, 92Sr, and 93Y in the fission of 235U and 238U by protons of energy from 20–85 MeV have been determined. Excitation functions and charge dispersion curves have been obtained. The most probable charge, Zp, moves closer to stability, ZA, with increasing energy. The values of ZA − Zp for the two fissioning systems are identical, unlike the situation in the heavy-mass region. The values of ZA − Zp for the light- and heavy-mass regions differ considerably, showing that the equal charge displacement hypothesis does not hold even at these moderate energies.

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