CC BY
14Complex Systems of Charged Particles and their Interactions with Electromagnetic Radiation 2018
ELECTRON DRIFT IN ARGON WITH IRON VAPOR
1 2,3 1 13
V.S. Kurbanismailov , S.A. Maiorov , O.A. Omarov , G.B. Ragimkhanov , Tereshonok D.V.
1Dagestan State University, str. M. Gadjieva 43a, Makhachkala, 367000, Russia, E-mail: gb-r@mail.ru
-Prokhorov General Physical Institute of the Russian Academy of Sciences, Vavilov Str. 38, Moscow, Russia -Joint Institute for High Temperatures ofthe Russian Academy of Sciences, Izhorskay Str.13, Moscow,125412 Russia
The properties of a gas-discharge plasma in a mixture of an inert gas in the presence of metal vapors are of great interest for variety of applications [1]. In addition, the process of formation and development of a pulsed discharge in an interelectrode gap can also be accompanied by sputtering of electrode [2]. Metal vapor, even at low concentrations, due to the lower ionization potential, significantly affect the kinetics of the discharge. In this paper, we consider, as an example, the drift of electrons in Ar with Fe vapor. Note, that Cu vapor lasers are very widely used, but theoretical and numerical results leave many questions [3,4,5].
The electron drift characteristics in argon with iron vapors are calculated and analyzed at reduced electric field strength in the range E / N = 1 - 2000 Td. The influence of the iron concentration on the kinetic characteristics of the discharge: the drift velocity, the average electron energy, the diffusion and mobility coefficients, the ionization frequency, and Townsend ionization coefficients is studied. Stoletov constant is also calculated. Particular attention is paid to the electron runaway effect.
A comparison of the electron distribution function with Maxwell and Druyvestein distributions is given. It is shown that even minor additions of iron atoms to argon, starting with a fraction of a percent, strongly influence the discharge, in particular, on the characteristics of inelastic processes.
In Fig. 1(left) shows the dependence of the drift velocity of the electrons, and in Fig. 2 (right) the coefficient of electron runaway from the reduced electric field strength E / N in pure argon, iron vapors and also in argon/ferrum mixture with 0.1%, 1%, 2%, 5%, 10% and 50% iron atoms content.
The results of the calculations give a fairly complete picture of the mechanism of the effect of small additions of iron vapors on the characteristics of a gas discharge. The most interesting and important fact from the practical point of view is a strong increase in the ionization frequency with an insignificant (on the order of fractions of a percent) addition of iron fumes. In addition, it should be noted that in this case, iron atoms will predominantly be ionized, respectively, iron ions will be mainly represented in the discharge.
It is shown that even small additions of copper atoms to helium, starting with a fraction of a percent, strongly influence the discharge, especially on the characteristics of inelastic processes.
E/N Td EN Td
This work was supported by the Russian Foundation for Basic Research, project № 18-08-00075a.
1. TarasenkoV,F., Yakovlenko S.I. // Physics - Uspekhi. -174. -No9. - P.953--2004.
2. Kurbanismailov V.S. et all.//Plasma physics reports. - - Vol. 42. - № 7. - P. 687-698. 2016.
3. Babich L P. //Physics - Uspekhi. - 2005. - Vol.175. - №10. - P.1069-1091.
4. Ulyanov K.N.// High temperature. - 2005. - Vol.43. - №5. - P. 645-656.
5. Stahl A., Hirvijoki E., Decker J., Embreus O., and Fulop T.// Phys. Rev. Lett. -2015. -Vol. 114. - P. 115002.
