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17Complex Systems of Charged Particles and their Interactions with Electromagnetic Radiation 2019
ELECTRON DRIFT IN NEON WITH IRON VAPORS: DRIFT VELOCITY, IONIZATION AND RUNAWAY COEFFICIENT
G. B. Ragimkhanov1, V.S. Kurbanismailov1, Z.R. Khalikova1, S.A. Maiorov23,
K.M. Turekhanova4
1Dagestan State University, Makhachkala, Russia, e-mail: gb-r@mail.ru Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia Joint Institute for High Temperature of the Russian Academy of Sciences, Moscow, Russia 4IETP, Al-Farabi Kazakh National University, Almaty, Kazakhstan
The properties of a gas-discharge plasma in an inert gas mixture in the presence of metal vapors are of great interest for a wide variety of applications [1]. In addition, the process of formation and development of a pulse discharge in the interelectrode gap can also be accompanied by sputtering of a metal electrode [2], and metal vapors, even in low concentrations, due to the lower ionization potential, significantly affect the discharge kinetics. In this paper, we consider the case of electron drift in argon with iron vapor as an example, since metal vapor lasers are widely used, and the results of theoretical studies and numerical simulations leave many unexplained questions [3, 4].
The Monte Carlo method calculated the kinetic characteristics of electron drift in neon in the presence of iron vapor at an electric field strength of E / N = 1 - 1000 Td taking into account inelastic collisions and analyzed the effect of metal vapor concentration on the drift velocity, average electron energy, and diffusion coefficients and mobility. In addition, the Townsend ionization coefficient and electron runaway, the electron energy distribution functions, were calculated and compared with the Maxwell and Druyvestein distributions. It has been shown that insignificant additions of iron atoms in neon, starting from fractions of a percent, strongly influence the discharge, in particular, on the characteristics of inelastic processes and charge composition.
1 Cl-
io
Fe
-■i+eiFe (50%)^-"' . • V.' ( 1% '— Ne ^fi&F« (1
10"
NeJFe i SCrtt) . NfifFa ( 1C:v: < ' ' h ' " '1 ■ r IV. y 1 '
Td
fig.1
fig.3
In fig. 1 shows the dependence of the electron drift velocity on the reduced electric field strength E / N in pure nejn, iron vapor, and also in a mixture of argon with 0.1%, 1%, 2%, 5%, 10%, 50% iron content, and in fig. 2 and fig. 3 - similar dependences of the reduced Townsend ionization coefficient and the electron runaway coefficient.
It has been shown that even insignificant additions of iron atoms to neon, starting from fractions of a percent, strongly affect the discharge, especially the characteristics of inelastic processes. The experimental part was supported by the Russian Foundation for Basic Research, project № 19-08-00611a.
References
[1] Tarasenko V.F., Yakovlenko S.I. // Physics Uspekhi. Vol.174. №9. P.953-971.
[2] Kurbanishmailov V.S. et al. // Plasma Physics Reports. 2016. Vol. 42. No. 7. P. 687-698.
[3] Babich L P. // Physics Uspekhi.2005. T.175. №10. P.1069-1091.
[4] Ulyanov K.N. // High Temperature. 2005. T.43. №5. P. 645-656.
