ELFT HÍRADÓ

[Szeminárium koordinátor <szfi-seminar AT wigner.mta.hu>]

SZFI SzemináriumDonkó ZoltánMTA Wigner FK SZFIMany-body effects in charged 
particle transport – the Coulomb logarithm and beyond2019. október 15. kedd, 
10.00, KFKI Telephely, I. épület 1. emeleti TanácsteremCoulomb collisions, at 
appreciable ratios of the electron to the neutral particle density, influence 
significantly the electron kinetics in particle swarms and in plasmas of gas 
discharges. In [1] a combination of Molecular Dynamics and Monte Carlo 
simulation techniques was introduced that provides a novel, 
approximation-free, first-principles calculation method for the velocity 
distribution function of electrons, and related swarm characteristics, at 
arbitrary degree of ionisation. In comparison with the solution of the 
Boltzmann transport equation this method was used in studies of the bistable 
solutions of the electron energy distribution function [2], as well as of 
negative differential conductivity and transient negative mobility effects in 
electron transport [3]. In our recent studies, we proposed a modification, 
due to electron – neutral collisions, of the classical Coulomb logarithm that 
enters the collision terms of the Boltzmann equation [4] and have shown that 
Boltzmann transport calculations using this modified Coulomb logarithm are in 
excellent agreement with those obtained from first-principles simulations 
that account for the many-body effects during the charged particle 
transport.[1] Z. Donkó: "First principles calculation of the effect of 
Coulomb collisions in partially ionized gases", Physics of Plasmas. 21, 43504 
(2014).[2] N. Dyatko and Z. Donkó: "Bistable solutions for the electron 
energy distribution function in electron swarms in xenon: a comparison 
between the results of first-principles particle simulations and conventional 
Boltzmann equation analysis", Plasma Sources Sci. Technol. 24, 45002 
(2015).[3] Z. Donkó and N. Dyatko: "First-principles particle simulation and 
Boltzmann equation analysis of negative differential conductivity and 
transient negative mobility effects in xenon", Eur. Phys. J. D 70, 135 
(2016).[4] G. J. M. Hagelaar, Z. Donkó, N. Dyatko: "Modification of the 
Coulomb Logarithm due to Electron-Neutral Collisions", Phys. Rev. Lett. 123, 
025004 (2019).   Minden érdeklődőt szívesen látunk! - Everyone is 
welcome to attend.Juhász Róbertszfi-seminar AT wigner.mta.hu