Simulation Studies of Collision Cascades in Liquid in Targets

1986 ◽  
Vol 74 ◽  
Author(s):  
D. Y. Loi ◽  
M. H. Shapiro ◽  
T. A. Tombrello ◽  
B. J. Garrison ◽  
N. Winograd
Keyword(s):  
Experimental Data ◽  
Surface Layer ◽  
Angular Distribution ◽  
Lower Energy ◽  
Atomic Layer ◽  
Angular Distributions ◽  
Recent Experimental Data ◽  
Simulation Studies ◽  
Detailed Structure ◽  
Multiple Interaction

AbstractMultiple interaction computer simulations have been used to determine the properties of collision cascades in liquid In targets induced by normally incident 5 keV Ar+ ions. Below the first atomic layer the cascade becomes Thompson-like relatively quickly. However, within the first atomic layer the angular distribution of moving atoms became forward peaked by 150 fs and remained so until,∼300 fs. Energy and angle resolved (EARN) spectra were calculated for the ejected atoms. The peak of the energy distribution shifted to lower energies at larger ejection angles, and the angular distributions became broader for lower energy particles. Both results agree with recent experimental data, and with a simple model proposed bg Garrison. Our results suggest that the detailed structure of the surface layer is very important in the sputtering process.

Computer Simulation of Sputtering from Two Component Liquid Metal Targets

1985 ◽  
Vol 63 ◽  
Author(s):  
M. H. Shapiro ◽  
D. Y. Lo ◽  
T. A. Tombrello
Keyword(s):  
Experimental Data ◽  
Angular Distributions ◽  
Good Qualitative Agreement ◽  
Energy Distributions ◽  
Pure Indium ◽  
Two Component ◽  
Similar Information ◽  
Indium Target ◽  
Multiple Interaction ◽  
Detailed Nature

ABSTRACTThe sputtering of In and Ga atoms from a “liquid” target composedof gallium coveredby a surface monolayer of indium by incident 5 keV Ar+ ions was simulated using the multiple interaction molecular dynamics technique. Yields, energy distributions, and angular distributions of sputtered atoms were obtained at a temperature above the melting point for the eutectic alloy. Similar information was obtained for a pure gallium and a pure indium target. Our results for layer yield ratios and angular distributions are in good qualitative agreement with Dumke's experimental data for the Ar+, In-Ga system. Absolute yields, however, were found to be sensitive to the detailed nature of the two-body potentials used to describe the atom-atom interactions.

scholarly journals Model for Describing Emission Characteristics of Electron-Beam Evaporation Sources

1979 ◽  
Vol 6 (1) ◽  
pp. 9-12
Author(s):  
Miklós Szilágyi
Keyword(s):  
Experimental Data ◽  
Electron Beam ◽  
Angular Distribution ◽  
Simple Model ◽  
Electron Beam Evaporation ◽  
Angular Distributions ◽  
Emission Characteristics

The experimental data for the anistropic component of the angular distribution of electron-beam evaporation sources are usually described in terms of thecosnθdependence. In this paper a simple model for calculating angular distributions is presented. The generally used dependence appears as a particular case in the model.

scholarly journals Angular Distribution of Characteristic Radiation Following the Excitation of He-Like Uranium in Relativistic Collisions

Atoms ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 20
Author(s):  
Alexandre Gumberidze ◽  
Daniel B. Thorn ◽  
Andrey Surzhykov ◽  
Christopher J. Fontes ◽  
Dariusz Banaś ◽  
...  
Keyword(s):  
Experimental Data ◽  
Angular Distribution ◽  
Theoretical Study ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Angular Distributions ◽  
Characteristic Radiation ◽  
Excitation Process ◽  
Excitation Processes ◽  
First Time

In this paper, we present an experimental and theoretical study of excitation processes for the heaviest stable helium-like ion, that is, He-like uranium occurring in relativistic collisions with hydrogen and argon targets. In particular, we concentrate on angular distributions of the characteristic Kα radiation following the K → L excitation of He-like uranium. We pay special attention to the magnetic sub-level population of the excited 1s2lj states, which is directly related to the angular distribution of the characteristic Kα radiation. We show that the experimental data can be well described by calculations taking into account the excitation by the target nucleus as well as by the target electrons. Moreover, we demonstrate for the first time an important influence of the electron-impact excitation process on the angular distributions of the Kα radiation produced by excitation of He-like uranium in collisions with different targets.

scholarly journals Measurements of the gamma-quanta angular distributions emitted from neutron inelastic scattering on 28Si

2018 ◽  
Vol 177 ◽  
pp. 02002
Author(s):  
N.A. Fedorov ◽  
D.N. Grozdanov ◽  
V.M. Bystritskiy ◽  
Yu.N. Kopach ◽  
I.N. Ruskov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Gamma Radiation ◽  
Inelastic Scattering ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Recent Experimental Data ◽  
Silicon Sample ◽  
Neutron Inelastic Scattering ◽  
Neutron Method ◽  
Good Agreement

The characteristic gamma radiation from the interaction of 14.1 MeV neutrons with a natural silicon sample is investigated with Tagged Neutron Method (TNM). The anisotropy of gamma-ray emission of 1.779 MeV was measured at 11 azimuth angles with a step of ∠15°. The present results are in good agreement with some recent experimental data.

Fusion and Breakup Reactions of 17S + 208Pb and 15C + 232ThHalo Nuclei Systems

2015 ◽  
Vol 11 (2) ◽  
pp. 2972-2978
Author(s):  
Fouad A. Majeed ◽  
Yousif A. Abdul-Hussien
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Fusion Reaction ◽  
Fusion Cross Section ◽  
Reaction Cross ◽  
Recent Experimental Data ◽  
Barrier Distribution ◽  
Coupled Channel ◽  
Total Fusion ◽  
Full Quantum

In this study the calculations of the total fusion reaction cross section have been performed for fusion reaction systems 17F + 208Pb and 15C + 232Th which involving halo nuclei by using a semiclassical approach.The semiclassical treatment is comprising the WKB approximation to describe the relative motion between target and projectile nuclei, and Continuum Discretized Coupled Channel (CDCC) method to describe the intrinsic motion for both target and projectile nuclei. For the same of comparsion a full quantum mechanical clacualtions have been preforemd using the (CCFULL) code. Our theorticalrestuls are compared with the full quantum mechaincialcalcuations and with the recent experimental data for the total fusion reaction  checking the stability of the distancesThe coupled channel calculations of the total fusion cross section σfus, and the fusion barrier distribution Dfus. The comparsion with experiment proves that the semiclassiacl approach adopted in the present work reproduce the experimental data better that the full quantal mechanical calcautions. 

SYSTEMATIC COMPARISON OF THE EXPERIMENTAL DATA WITH THE FRITIOF MODEL IN NUCLEUS–NUCLEUS INTERACTIONS WITH LIGHT AND HEAVY TARGET NUCLEI IN NUCLEAR EMULSION AT 4.5A Gev/c

2002 ◽  
Vol 11 (02) ◽  
pp. 161-175 ◽  
Author(s):  
M. MOHERY ◽  
N. N. ABD-ALLAH
Keyword(s):  
Experimental Data ◽  
Nuclear Emulsion ◽  
Multiplicity Distribution ◽  
Angular Distributions ◽  
Target Groups ◽  
Systematic Comparison ◽  
Secondary Particles ◽  
Heavy Target ◽  
Light Target ◽  
Fritiof Model

The characteristics of the interactions of 4.5 A GeV/c 28 Si nuclei with emulsion have been investigated. The method of separating interactions into those with hydrogen, light and heavy target nuclei has been discussed. The multiplicity distribution, average multiplicities, multiplicity correlation and the angular distributions of the secondary particles emitted in 28 Si -emulsion are calculated according to the Modified Fritiof Model and compared with the experimental data and with other available data for p, 12 C , 24 Mg at the same energy. It has been found that the modified Fritiof model can describe the multiplicity characteristics of the different emitted particles in the above-mentioned interaction with different target groups. The comparison of the experimental data with the modified Fritiof model shows no clear preference for the case of the light target while it seems to be nearer to the experimental data in the case of the heavy target and the emulsion

THE ANGULAR DISTRIBUTION OF PHOTOFISSION FRAGMENTS

1959 ◽  
Vol 37 (12) ◽  
pp. 1418-1437 ◽  
Author(s):  
A. P. Baerg ◽  
R. M. Bartholomew ◽  
F. Brown ◽  
L. Katz ◽  
S. B. Kowalski
Keyword(s):  
Angular Distribution ◽  
Low Energy ◽  
Photon Beam ◽  
Angular Distributions ◽  
Bremsstrahlung Energy ◽  
Isotropic Distribution ◽  
Degree Of Anisotropy ◽  
Maximum Bremsstrahlung Energy

Angular distributions of photofission fragments relative to the photon beam have been measured as a function of maximum bremsstrahlung energy in the range 6–20 Mev. The nuclides U-233, U-235, Np-237, Pu-239, and Am-241 give an isotropic distribution at all energies studied. The nuclides Th-232, U-234, U-236, U-238, and Pu-240 give anisotropic distributions which can be described by an equation of the form W(θ) = 1 + α sin2 θ where θ is the angle between fragment and beam. The degree of anisotropy is large at low energy and falls rapidly as the energy is increased. At a given energy Th-232 has the greatest degree of anisotropy and Pu-240 the least.

THE ANGULAR DISTRIBUTION OF FAST PHOTONEUTRONS FOR NUCLIDES WITH N ABOUT 56

1967 ◽  
Vol 45 (9) ◽  
pp. 2851-2857
Author(s):  
S. M. Hussain ◽  
K. G. McNeill
Keyword(s):  
Angular Distribution ◽  
Angular Distributions

Measurements have been made of the angular distributions of fast (E > 5 MeV) photoneutrons from eight elements in the region Z = 28 to Z = 50, and from lead, using threshold detectors. It is found that there is evidence for peaking of the anisotropy of these photoneutrons at the closing of the. N = 56 subshell.

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