Hydrogen dissociation degree in the Grimm-type glow discharge measured by optical emission spectroscopy

• Published in: The European physical journal. D, Atomic, molecular, and optical physics Atomic, molecular, and optical physics, 2023-07, Vol.77 (7), Article 130
• Main Authors: Vasiljević, Milica M., Majstorović, Gordana Lj, Videnović, Ivan R., Spasojević, Djordje
• Format: Article
• Language: English
• Subjects: Applications of Nonlinear Dynamics and Chaos Theory; Argon; Atomic; Cathodes; Electric field strength; Electron energy; Emission spectroscopy; Glow discharges; H alpha line; Low pressure; Molecular; Optical and Plasma Physics; Optical emission spectroscopy; Physical Chemistry; Physics; Physics and Astronomy; Physics of Ionized Gases and Spectroscopy of Isolated Complex Systems: Fundamentals and Applications; Quantum Information Technology; Quantum Physics; Regular Article – Plasma Physics; Sheaths; Spectroscopic analysis; Spectroscopy/Spectrometry; Spintronics
• ISSN: 1434-6060; 1434-6079
• DOI: 10.1140/epjd/s10053-023-00704-7

The hydrogen dissociation degree is measured by means of optical emission spectroscopy in the cathode sheath of cylindrical abnormal Grimm-type DC glow discharge operating in the hydrogen–argon mixture at low pressure. The degree of dissociation, ranging from 80% in the close vicinity of the cathode and decreasing to 60% towards the negative glow, is obtained from the intensity ratio of the hydrogen Balmer H γ line and the diagonal Fulcher-α molecular bands. The cathode sheath thickness is extracted from the electric field strength distribution measured using Stark spectroscopy of the hydrogen Balmer H α line. An electron temperature of 2.7 eV in the negative glow region is estimated by observing the intensity ratio of the diagonal Fulcher-α bands and the H α line. Graphical Abstract