Effects of level density in the cross sections of (α, xn), (α, pxn), (α, 2pxn) and (α, αxn) reactions in 197Au, 181Ta, natIn and 93Nb and pre-equilibrium analysis

2009 ◽  
Vol 87 (9) ◽  
pp. 1037-1046 ◽  
Author(s):  
N. L. Singh ◽  
S. Mukherjee
Keyword(s):  
Monte Carlo Simulation ◽  
Cross Sections ◽  
Neutron Emission ◽  
Level Density ◽  
The Other ◽  
Equilibrium Analysis ◽  
Simulation Code ◽  
Semiclassical Model ◽  
Γ Ray ◽  
Good Agreement

Excitation functions are measured for α-particle-induced reactions on 197Au, 181Ta, natIn, and 93Nb in the energy region 18 to 60 MeV using the activation method and γ-ray spectrometry. The experimental results are compared with semiclassical model codes, STAPRE, ALICE-91, and COMPLET. These models take into account compound nuclei as well as pre-equilibrium emissions. The angular momentum removal effects have also been included in the COMPLET code. The Monte Carlo simulation code PACE4 is also employed for the calculations of equilibrium cross sections. In the case of neutron emission channels, both the model codes give fairly good agreement. The COMPLET code on the other hand, explains the α-particle emission channels in a more convincing manner.

scholarly journals A Monte-Carlo Simulation of the Behaviour of Electron Swarms in Hydrogen Using an Anisotropic Scattering Model

1978 ◽  
Vol 31 (4) ◽  
pp. 299 ◽  
Author(s):  
HA Blevin ◽  
J Fletcher ◽  
SR Hunter
Keyword(s):  
Experimental Data ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Electron Transport ◽  
Anisotropic Scattering ◽  
Isotropic Scattering ◽  
Transport Parameters ◽  
Simulation Code ◽  
Scattering Model ◽  
Good Agreement

Hunter (1977) found that a Monte-Carlo simulation of electron swarms in hydrogen, based on an isotropic scattering model, produced discrepancies between the predicted and measured electron transport parameters. The present paper shows that, with an anisotropic scattering model, good agreement is obtained between the predicted and experimental data. The simulation code is used here to calculate various parameters which are not directly measurable.

scholarly journals CROSS-SECTIONS FOR PHOTONUCLEAR REACTIONS 93Nb(γ,n)92mNb AND 93Nb(γ,n)92tNb IN THE END-POINT BREMSSTRAHLUNG ENERGIES 36...91 MeV

2020 ◽  
pp. 148-153
Author(s):  
A.N. Vodin ◽  
O.S. Deiev ◽  
I.S. Timchenko ◽  
S.N. Olejnik ◽  
A.S. Kachan ◽  
...  
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Maximum Energy ◽  
Reaction Cross ◽  
Bremsstrahlung Spectrum ◽  
Photonuclear Reactions ◽  
End Point ◽  
Γ Ray ◽  
First Time ◽  
Good Agreement

The flux-weighted averaged over the energy range of bremsstrahlung spectrum from reaction threshold up to the maximum energy of γ-ray cross-sections <σ(E)> of the 93Nb(γ,n)92mNb and 93Nb(γ,n)92tNb photonuclear reactions were determined by the gamma-activation method within the end-point bremsstrahlung energies Еmax = 36…91 MeV. Activation of 93Nb targets has been done by a bremsstrahlung flux using an electron beam at the linear accelerator LUE-40 at RDC "Accelerator" NSC KIPT. The γ-ray spectra of irradiated targets were registered using the HPGe detector with an energy resolution of 1.8 keV for the 1332 keV line 60Co. To control the bremsstrahlung flux we used natMo witness-targets and a reaction cross-section of 100Mo(γ,n)99Mo. Obtained experimental cross-sections <σ(E)> of the studied reactions are in good agreement with the theoretical values calculated within TALYS 1.9 code and the results of other authors. The averaged cross-sections <σ(E)> of the 93Nb(γ,n)92mNb and 93Nb(γ,n)92tNb reactions in the energy range 35...45 MeV and > 70 MeV were obtained for the first time.

EXCITATION FUNCTIONS OF ALPHA INDUCED REACTIONS ON NATURAL NICKEL UP TO 50 MeV

2005 ◽  
Vol 14 (04) ◽  
pp. 611-629 ◽  
Author(s):  
N. L. SINGH ◽  
S. MUKHERJEE ◽  
M. S. GADKARI
Keyword(s):  
Angular Momentum ◽  
Alpha Particle ◽  
Gamma Ray ◽  
Level Density ◽  
The Other ◽  
Gamma Ray Spectrometry ◽  
Excitation Functions ◽  
Classical Models ◽  
Nucleon Emission ◽  
Good Agreement

Excitation functions have been measured for alpha-particle induced reactions on natural nickel leading to the production of 62 Zn , 61 Cu , 56,57 Ni and 56,58 Co radioisotopes up to 50 MeV by the activation method and gamma-ray spectrometry. Most of these radioisotopes are produced by one or two alpha-particle emissions and a few nucleon emissions. The excitation functions were compared with semi-classical models codes, like ALICE/90, which includes a shell corrected level density formulation and the COMPLET, which takes into account angular momentum removal effects. In the case of multi-nucleon emission channels, ALICE/90 gives fairly good agreement. The COMPLET code on the other hand, explains the α-particle emission channels in a more convincing manner.

A MONTE CARLO SIMULATION OF THE COSMIC RAYS INTERACTIONS WITH THE EARTH'S ATMOSPHERE

2002 ◽  
Vol 17 (12n13) ◽  
pp. 1625-1634 ◽  
Author(s):  
P. ZUCCON
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Particle Production ◽  
Nuclear Interaction ◽  
Atmospheric Density ◽  
Simulation Code ◽  
Geomagnetic Cutoff ◽  
The Impact ◽  
Production Mechanisms ◽  
Good Agreement

Substantial fluxes of protons and leptons with energies below the geomagnetic cutoff have been measured by the AMS experiment at altitudes of 370-390 Km, in the latitude interval ±51.7°. The production mechanisms of the observed trapped fluxes are investigated in detail by means of the FLUKA Monte Carlo simulation code. All known processes involved in the interaction of the cosmic protons with the atmosphere (detailed descriptions of the magnetic field atmospheric density, as well as the electromagnetic and nuclear interaction processes) are included in the simulation. The results are presented and compared with the experimental data, indicating good agreement with the observed fluxes. The impact of secondary proton flux on particle production in atmosphere is briefly discussed.

SIMULATION OF ELECTRON SWARM PARAMETERS IN AIR

2006 ◽  
Vol 20 (10) ◽  
pp. 1233-1242 ◽  
Author(s):  
A. SETTAOUTI ◽  
L. SETTAOUTI
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Electric Field ◽  
Cross Sections ◽  
Uniform Electric Field ◽  
Number Density ◽  
Gas Molecules ◽  
Experimental Values ◽  
Background Gas ◽  
Good Agreement

The electron transport of air in a uniform electric field is investigated by a Monte–Carlo simulation. The simulation results obtained are compared with the available data in the literature. The result of Monte–Carlo simulation shows that electron molecule collision cross sections adopted in the simulation result in good agreement with the experimental values over the range of E/N investigated (E is the electric field and N is the gas number density of background gas molecules).

Revisiting cross sections for proton induced reactions on natural lead between 10 and 80 MeV

2021 ◽  
Vol 109 (4) ◽  
pp. 233-242
Author(s):  
Salim Gülez ◽  
Bhawna Pandey ◽  
Erik Strub
Keyword(s):  
Cross Sections ◽  
Additional Data ◽  
Historical Data ◽  
Theoretical Calculations ◽  
Historical Record ◽  
High Proton ◽  
Γ Ray ◽  
Proton Induced Reactions ◽  
Good Agreement

Abstract This work is focused on the natPb(p,xn)207Bi reaction to extend earlier works on proton induced reactions for the determination of cross sections of residual nuclides. 207Bi decay (half-life 31.55 years) was measured by γ-ray spectrometry in 42 lead foils which had been irradiated by high proton fluxes 20 years ago. Since then, all short-lived radionuclides produced during the irradiation have decayed, so the background is strongly reduced and the cross section could be measured more precisely than during the original measurements. The results are found to be in very good agreement with the historical record. Additionally, theoretical calculations with modern Monte Carlo based codes were performed to compare the calculations of various Bi, Tl and Pb reactions with the historical data and with additional data from literature. The deviations of the new data from both theoretical calculations using EMPIRE and TALYS are discussed.

Decay Schemes for the Isomers of 148Pm and the Cross Sections for their Production by Neutron Capture in 147Pm

1971 ◽  
Vol 49 (1) ◽  
pp. 108-117 ◽  
Author(s):  
R. S. Mowatt ◽  
W. H. Walker
Keyword(s):  
Neutron Flux ◽  
Cross Sections ◽  
Neutron Capture ◽  
Decay Scheme ◽  
Production Cross ◽  
Thermal Reactor ◽  
Small Correction ◽  
Γ Ray ◽  
Neutron Cross Sections ◽  
Good Agreement

The γ-ray spectra arising from the decay of 41-day 148Pmm and 5-day 148Pmg produced by the irradiation of 2.6-year 147Pm in a thermal reactor neutron flux have been measured with a Ge(Li) detector. The absolute probabilities for γ-ray emission were determined from an analysis of the spectra and used to construct an improved decay scheme for the two isomers and to obtain their production cross sections. The 147Pm thermal neutron cross sections obtained after making a small correction for epithermal capture are 84 ± 10 b and 72.4 ± 3.0 b for the production of the 148Pmg and 148Pmm activities respectively, in good agreement with the results of Fenner and Large, but significantly smaller than other recent measurements.

scholarly journals Resonance Parameters for Uranium 233

1967 ◽  
Vol 20 (6) ◽  
pp. 617 ◽  
Author(s):  
AR de L Musgrove
Keyword(s):  
Least Squares ◽  
Cross Sections ◽  
Least Squares Method ◽  
The Other ◽  
Resonance Parameters ◽  
Single Level ◽  
Channel Theory ◽  
Good Agreement

Single-level and multilevel resonance parameters are given for 233U below 11 e V_ The total and fission cross sections were fitted simultaneously and good agreement was obtained. Spin assignments determined by the least squares method support the prediction of the channel theory of fission that 233U has two level populations; one with predominantly large fission widths and the other with much narrower widths.

Proton-deuteron interactions at 970 MeV

1959 ◽  
Vol 251 (1265) ◽  
pp. 233-246 ◽  
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Meson Production ◽  
The Other ◽  
Isotopic Spin ◽  
Nuclear Forces ◽  
Proton Proton ◽  
Pressure Diffusion ◽  
Charge Independence ◽  
Good Agreement

A high-pressure diffusion cloud chamber has been used to study the interactions of 970 MeV protons from the Birmingham synchrotron with deuterium. Analysis of the 569 collisions observed indicates that at this energy the deuteron behaves as if it were composed of two free nucleons. The properties of proton-proton and proton-neutron scattering have been determined on this assumption. An estimate is made of the extent of the ‘shadowing’ of each nucleon in the deuteron by the other. The partial cross-sections for p-p and p-n elastic scattering have been determined, as have also the values for the five possible single meson production processes. They have the following ‘best’ values: (1) ( p + p-> p + p ) = 25.9 + 1.7 mb, (2) ( p + n-> p + n ) = 16.2 + 3.5 mb, (3) ( p + p-> p + p + 7T 0 ) = 5.4 + 1.0 mb, (4) ( p + p -> n + p + 7T + ) = 15.6 + 1.7 mb, (5) ( p + n-> p + n + n 0 ) = 14.3 + 3.5 mb, (6) ( p + n-+ p + p + 7T - ) = 2.7 + 0.6mb, (7) ( p + n-> n + n + 7T + ) = 4.3 + 1.1 mb. Double meson production and reactions involving secondary deuterons are not important. The cross-sections (1), (2), (3), (4) and (5) are consistent with values extrapolated from data at energies below 660 MeV by Russian workers. Knowledge of the other cross-sections (6) and (7) makes possible a test of the validity of the charge independence of nuclear forces. The present results are not in good agreement with this. The results for inelastic scattering indicate that, assuming charge independence, the formation of excited nucleons of isotopic spin 3/2 does not dominate the process of pion production. This is also true for the Russian data. Twelve cases of double meson production were observed. The angular distribution of proton-neutron elastic scattering has the form expected from lower energy data.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

Sign in / Sign up

Export Citation Format

Share Document