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In the preparation and research of high-temperature plasma for magnetic confinement fusion, wall conditioning is an important and necessary procedure. There are various methods for wall conditioning, one of which is glow discharge [1, 2]. Hydrogen or helium are usually used as working gases in glow discharge. A glow discharge is also used in the boronization procedure [3-5]. In this case, a mixture of helium and diborane can be used, which releases hydrogen upon dissociation. Therefore, it is necessary to conduct research on glow discharge in a mixture of hydrogen and helium.
This paper presents the first results of a research study on glow discharge plasma in a mixture of helium and hydrogen, with hydrogen concentrations in the mixture from 25% to 75%. The experiments were conducted in the pressure range of ~ 0.3 - 13 Pa and the discharge current range from 0.1 to 1 A. Measured breakdown voltage, volt-ampere characteristics of discharges, plasma parameters using a triple probe, and determined the composition of plasma using optical emission spectroscopy. A comparative analysis of discharge and plasma parameters for a mixture of He+H2 with parameters in pure hydrogen and helium was performed.
References:
1. Wauters T. et al. Wall conditioning in fusion devices with superconducting coils. Plasma Physics and Controlled Fusion. 2020. № 62 (3). С. 034002.
2. Yu. Martsenuik et al. Upgrade glow discharge cleaning system on the Uragan-2M stellarator. 51st EPS Conference on Plasma Physics, Vilnius, Lithuania, July, 2025. 2 P 110.
3. Winter, J. et al. "Boronization in TEXTOR." Journal of Nuclear Materials 162 (1989): 713-723.
4. Schneider, U. et al. "Boronization of ASDEX." Journal of nuclear materials 176 (1990): 350-356.
5. Schneider, U. and J. Stadlbauer. "Boronization on Wendelstein 7-AS." Fusion Technology 1992. North-Holland, 1993. 376-380.