Signature of fast H atoms from cathode glow region of a dc discharge

Journal Article · Fri May 15 04:00:00 EDT 2009 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3080196· OSTI ID:21277116

Bharathi, P; Suraj, K S; Prahlad, V; Mukherjee, S; Vasu, P ^[1]

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1. Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

Asymmetric broadening of H{sub {alpha}} line from cathode glow region has been studied. In the cathode glow, mean energy and fractional population of very fast hydrogen atoms were found to be {approx}130 eV and {approx}55%, respectively. These values reduced to {approx}90 eV and {approx}20% when measured at negative glow region. The observed asymmetry was attributed to the presence of the fast hydrogen atoms near the cathode surface. The mean energy and number density of excited fast hydrogen atoms were estimated from the velocity distribution of H{sup +}, H{sub 2}{sup +}, and H{sub 3}{sup +} considering collisions inside the cathode sheath. The reduction in the mean energy and number density of the excited fast hydrogen atoms, at the other locations of the discharge, was explained by energy relaxation and thermalization of the neutrals with the background gas.

• OSTI ID: 21277116
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 16; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ASYMMETRY
CATHODES
GLOW DISCHARGES
HYDROGEN
LINE BROADENING
PLASMA SHEATH