Eur. Phys. J. D (2014) 68: 60
https://doi.org/10.1140/epjd/e2014-40772-8

Regular Article

Spectroscopic and electric characterization of an atmospheric pressure segmented gas discharge with micro hollow electrodes

University of Belgrade, Faculty of Physics, P.O. Box 368, 11001 Belgrade, Serbia

^a e-mail: nikruz@ff.bg.ac.rs

Received: 9 December 2013
Received in final form: 16 January 2014
Published online: 21 March 2014

Abstract

We present the results of an optical emission spectroscopy and electric study of segmented micro hollow gas discharge source (SMHGD) operating at atmospheric pressure in DC regime. This microdischarge source with 1 mm discharge channel consists of five metal discs separated by alumina. Three central discs are made of copper while stainless steel was used for the cathode and anode. In order to perform side on measurements, 1.5 mm diameter side hole was drilled through central copper disc. The electron temperature (T_e), gas temperature (T_g) and electron number density (N_e) were measured in argon, argon-hydrogen and helium SMHGDs operating in the voltage range (220 to 475) V and currents 40 mA, 60 mA and 80 mA. Boltzmann plots of relative Ar I and He I line intensities were used to measure T_e = (3700–5500) K in argon and (2500–2800) K in helium SMHGDs. Same technique is applied to N₂ (C³ Π_u-B³ Π _g ) band to measure T_g in the range (700–900) K in Ar and He and (1400–1600) K in Ar-H₂ mixture. Line profiles of hydrogen the H_β line in argon and the ratio of He I 447.1 nm line intensity and its forbidden component in helium are employed to determine N_e ≈ (2–4) × 10¹⁴ cm^-3 in the center of SMHGD. By measuring SMHGD disc voltages, the longitudinal distribution of plasma potential and electric field strength are determined.