scholarly journals Comparison between the Boltzmann and Monte Carlo Simulation Methods for the Determination of Electron Swarm Transport Coefficients in Molecular Hydrogen

1979 ◽  
Vol 32 (3) ◽  
pp. 255 ◽  
Author(s):  
Ivan D Reid ◽  
Scott R Hunter
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Numerical Solution ◽  
Transport Properties ◽  
Cross Sections ◽  
Molecular Hydrogen ◽  
Transport Coefficients ◽  
Simulation Methods ◽  
Boltzmann's Equation

The transport properties of an electron swarm drifting and diffusing in hydrogen as determined from a numerical solution of Boltzmann's equation are compared with those derived previously from a Monte Carlo simulation. The same set of cross sections has been used with each method to calculate transport coefficients in the range 0�5 .;;; EIN.;;; 200 Td. The comparison shows that the Boltzmann analysis is valid in this case whenever ionization is not significant.

scholarly journals The interpretation and analysis of diffuse scattering using Monte Carlo simulation methods

2007 ◽  
Vol 64 (1) ◽  
pp. 23-32 ◽  
Author(s):  
T. R. Welberry ◽  
D. J. Goossens
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Diffuse Scattering ◽  
Simulation Methods ◽  
Neutron Sources ◽  
X Ray ◽  
Average Structure

Studies of diffuse scattering had a prominent place in the first issue ofActa Crystallographica60 years ago at a time when conventional crystallography (determination of the average structure from Bragg peaks) was in its infancy. Since that time, conventional crystallography has developed enormously while diffuse-scattering analysis has seemingly lagged well behind. The paper highlights some of the extra difficulties involved in the measurement, interpretation and analysis of diffuse scattering and plots the progress that has been made. With the advent of the latest X-ray and neutron sources, area detectors and the ever-increasing power of computers, most disorder problems are now tractable. Two recent contrasting examples are described which highlight what can be achieved by current methods.

scholarly journals The determination of low energy electron-molecule cross sections via swarm analysis

2008 ◽  
Vol 6 (1) ◽  
pp. 57-69 ◽  
Author(s):  
S. Dujko ◽  
R.D. White ◽  
Z.Lj. Petrovic
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Boltzmann Equation ◽  
Electron Transport ◽  
Cross Sections ◽  
Low Energy ◽  
Energy Electron ◽  
The Boltzmann Equation ◽  
Low Energy Electron

In this paper we discuss the swarm physics based techniques including the Boltzmann equation analysis and Monte Carlo simulation technique for determination of low energy electron-molecule cross sections. A multi term theory for solving the Boltzmann equation and Monte Carlo simulation code have been developed and used to investigate some critical aspects of electron transport in neutral gases under the varying configurations of electric and magnetic fields when non-conservative collisions are operative. These aspects include the validity of the two term approximation and the Legendre polynomial expansion procedure for solving the Boltzmann equation, treatment of non-conservative collisions, the effects of a magnetic field on the electron transport and nature and difference between transport data obtained under various experimental arrangements. It was found that these issues must be carefully considered before unfolding the cross sections from swarms transport data.

scholarly journals An Investigation of the Accuracy of Numerical Solutions of Boltzmann's Equation for Electron Swarms in Gases with Large Inelastic Cross Sections

1979 ◽  
Vol 32 (3) ◽  
pp. 231 ◽  
Author(s):  
Ivan D Reid
Keyword(s):  
Monte Carlo Simulation ◽  
Cross Sections ◽  
Numerical Solutions ◽  
Transport Coefficients ◽  
Distribution Functions ◽  
Monte Carlo Simulation Technique ◽  
Energy Distribution Functions ◽  
Boltzmann's Equation ◽  
Term Approximation ◽  
Boltzmann’S Equation

A Monte Carlo simulation technique has been used to test the accuracy of electron energy distribution functions and transport coefficients calculated using conventional numerical solutions of Boltzmann's equation based on a two-term approximation. The tests have been applied to a number of model gases, some of which have characteristics close to those of real gases, and include cases where the scattering is anisotropic. The results show that, in general, previous application of the numerical solution to real gases has been valid.

Electron Scattering in Solids

1990 ◽  
Vol 48 (2) ◽  
pp. 4-5
Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Angular Distribution ◽  
Elastic Scattering ◽  
Electron Scattering ◽  
Cross Sections ◽  
Expansion Method ◽  
Electron Excitation ◽  
Partial Wave Expansion ◽  
Backscattered Electrons

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

Development of SiO2 based doped with LiF, Cr2O3, CoO4 and B2O3 glasses for gamma and fast neutron shielding

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bünyamin Aygün ◽  
Erdem Şakar ◽  
Abdulhalik Karabulut ◽  
Bünyamin Alım ◽  
Mohammed I. Sayyed ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Fast Neutron ◽  
Cross Sections ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
Neutron Shielding ◽  
Shielding Properties ◽  
Effective Neutron ◽  
Simulation Codes

AbstractIn this study, the fast neutron and gamma-ray absorption capacities of the new glasses have been investigated, which are obtained by doping CoO,CdWO4,Bi2O3, Cr2O3, ZnO, LiF,B2O3 and PbO compounds to SiO2 based glasses. GEANT4 and FLUKA Monte Carlo simulation codes have been used in the planning of the samples. The glasses were produced using a well-known melt-quenching technique. The effective neutron removal cross-sections, mean free paths, half-value layer, and transmission numbers of the fabricated glasses have been calculated through both GEANT4 and FLUKA Monte Carlo simulation codes. Experimental neutron absorbed dose measurements have been carried out. It was found that GS4 glass has the best neutron protection capacity among the produced glasses. In addition to neutron shielding properties, the gamma-ray attenuation capacities, were calculated using newly developed Phy-X/PSD software. The gamma-ray shielding properties of GS1 and GS2 are found to be equivalent to Pb-based glass.

scholarly journals Determination of electron backscattering coefficient of beryllium by a high-precision Monte Carlo simulation

2021 ◽  
Vol 26 ◽  
pp. 100862
Author(s):  
Abrar Hussain ◽  
Lihao Yang ◽  
Shifeng Mao ◽  
Bo Da ◽  
Károly Tőkési ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
High Precision ◽  
Backscattering Coefficient ◽  
Electron Backscattering
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