Software tool for advanced Monte Carlo simulation of electron scattering in EBL and SEM: CHARIOT

Author(s):  
Sergey V. Babin ◽  
S. Borisov ◽  
E. Cheremukhin ◽  
Eugene Grachev ◽  
V. Korol ◽  
...  
Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding

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.


1999 ◽  
Vol 5 (S2) ◽  
pp. 80-81
Author(s):  
John Henry J. Scott ◽  
Robert L. Myklebust ◽  
Dale E. Newbury

Monte Carlo simulation of electron scattering in solids has proven valuable to electron microscopists for many years. The electron trajectories, x-ray generation volumes, and scattered electron signals produced by these simulations are used in quantitative x-ray microanalysis, image interpretation, experimental design, and hypothesis testing. Unfortunately, these simulations are often computationally expensive, especially when used to simulate an image or survey a multidimensional region of parameter space.Here we present techniques for performing Monte Carlo simulations in parallel on a cluster of existing desktop computers. The simulation of multiple, independent electron trajectories in a sample and the collateral calculation of detected x-ray and electron signals falls into a class of computational problems termed “embarrassingly parallel”, since no information needs to be exchanged between parallel threads of execution during the calculation. Such problems are ideally suited to parallel multicomputers, where a manager process distributes the computational burden over a large number of nodes.


1997 ◽  
Vol 04 (05) ◽  
pp. 955-958 ◽  
Author(s):  
K. TÖKÉSI ◽  
L. KÖVÉR ◽  
D. VARGA ◽  
J. TÓTH ◽  
T. MUKOYAMA

The energy distribution of the electrons backscattered in the direction of the surface normal of polycrystalline silver samples was studied using reflected electron energy loss spectroscopy (REELS) at 200 eV and 2 keV primary beam energies. For modeling the electron scattering processes, the Monte Carlo simulation technique was used and the REELS spectra were calculated at various (25°, 50° and 75°, with respect to the surface normal) angles of primary beam incidence. The effects of the surface energy loss process in REELS are evaluated from the comparison of the experimental and simulated spectra.


2000 ◽  
Vol 8 (2) ◽  
pp. 34-35
Author(s):  
John Henry J. Scott ◽  
Robert L. Myklebust ◽  
Dale E. Newbury

Monte Carlo simulation of electron scattering in solids has proven valuable to electron microscopists for many years. The electron trajectories, x-ray generation volumes, and scattered electron signals produced by these simulations are used in quantitative x-ray microanalysis, image interpretation, experimental design, and hypothesis testing. Unfortunately, these simulations are often computationally expensive, especially when used to simulate an image or survey a multidimensional region of parameter space.Here we present techniques for performing Monte Carlo simulations in parallel on a cluster of existing desktop computers. The simulation of multiple, independent electron trajectories in a sample and the collateral calculation of detected xray and electron signals fall into a class of computational problems termed “embarrassingly parallel”, since no information needs to be exchanged between parallel threads of execution during the calculation.


2016 ◽  
Vol 58 (10) ◽  
pp. 955-959 ◽  
Author(s):  
Nika Guberina ◽  
Saravanabavaan Suntharalingam ◽  
Kai Naßenstein ◽  
Michael Forsting ◽  
Jens Theysohn ◽  
...  

1994 ◽  
Vol 72 (5-6) ◽  
pp. 210-214 ◽  
Author(s):  
A. M. Al-Harkan

Internal and external optical bremsstrahlung accompanying the β decay of polarized nuclei were investigated. The features of angular distribution of light photons were analyzed taking into account multiple electron scattering. Monte-Carlo simulation was used to study the fate of β electrons and to calculate the intensity and angular distribution of the optical photons. It is shown that in pure water, the contribution of secondary electrons in the production of photons reaches 30–40%. We suggest using the angular distribution of optical photons to study the polarization states of β isotopes imbedded in transparent media.


1998 ◽  
Vol 37 (Part 1, No. 11) ◽  
pp. 6170-6176 ◽  
Author(s):  
Alexandre Palov ◽  
Haruhisa Fujii ◽  
Sanju Hiro

Author(s):  
Vladimir Abdrakhmanov ◽  
◽  
Dmitry Abdrakhmanov ◽  
Dmitry Zav’yalov ◽  
Vladimir Konchenkov ◽  
...  

The development of a software package using the OpenACC parallel computing technology for Monte Carlo simulation of the kinetic coefficients of homogeneous semiconductor materials is presented. The package is a set of interconnected classes, the parameters of the material and external fields are redefined in the child classes available to the user, which makes it possible to model a wide range of materials. The package allows us to use models of elastic (acoustic phonons, charged impurities) and inelastic (polar and nonpolar optical phonons) electron scattering in the single-band approximation. The use of OpenACC technology makes it possible to use both shared memory systems and hybrid systems equipped with graphics processors as a computing platform. The possibility of saving data about each particle at each time step of the simulation is provided. It allowed, in particular, to trace the dependence of the average collision frequency of the energy of charge carriers and strength of the DC electric field applied to the sample, in the beta-modification of gallium oxide, to assess the applicability of the conductivity models offered by other research groups. It is shown that the greatest contribution to the conductivity of the beta modification of gallium oxide at room temperatures is made by the scattering of electrons on polar optical phonons, and the average collision frequency, as well as the percentage of collisions of an electron with various types of inhomogeneities of the crystal lattice, weakly depend on the strength of the constant electric field. At a temperature of about 100 K, with an increase in the constant electric field applied to the sample, firstly, the proportion of scattering with the emission of polar optical phonons increases significantly and the proportion of scattering on charged impurities decreases, and secondly, the total frequency of collisions increases. This is due, on the one hand, to the heating of the electron gas by an electric field and the activation of scattering channels with the emission of a phonon at a given temperature, on the other hand, to an insufficiently rapid increase in the concentration of current carriers due to the ionization of impurities. Thanks to the Monte Carlo simulation, it was possible to directly evaluate the validity of the use of the Farvaque correction for an approximate description of the processes of inelastic electron scattering on polar optical phonons by introducing some effective relaxation time.


1981 ◽  
Vol 52 (12) ◽  
pp. 7403-7408 ◽  
Author(s):  
Masatoshi Kotera ◽  
Kenji Murata ◽  
Koichi Nagami

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