Balmer-alpha emission and hydrogen-atom energy in ion-source discharges

Journal Article · Thu Apr 01 00:00:00 EST 1982 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.25.2152· OSTI ID:5199226

McNeill, D H; Kim, J

The structure of the hydrogen Balmer-alpha line emission profiles from three types of neutral-beam-injector ion-source plasmas (filling pressure approx.10 mTorr, electron density approx.(1--2) x 10/sup 12/ cm/sup -3/, electron temperature approx.2--4 eV) is studied with the aid of a simple model for the neutral-particle balance and H/sub ..cap alpha../ emission. This model includes molecular and atomic reactions, wall interactions, and nonthermal electrons. A large fraction of the H/sub ..cap alpha../ is produced by dissociative excitation of H/sub 2/ and dissociative recombination of H/sub 2/ /sup +/, while the remainder is produced by excitation of H atoms, most of which have energies that are close to the characteristics H/sub 2/ dissociation energies. The H/sub ..cap alpha../ linewidth is thus insensitive to the discharge operating conditions and equals approx.0.27 A when only slow (approx.0.3 eV) dissociatively excited atoms are present or approx.0.35 A when fast (>1 eV) atoms, apparently also produced in dissociation reactions, are present as well.

• Research Organization: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
• OSTI ID: 5199226
• Journal Information: Phys. Rev. A; (United States), Vol. 25:4
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
HYDROGEN
BALMER LINES
HYDROGEN IONS
ION SOURCES
ELECTRIC DISCHARGES
EXCITATION
LINE WIDTHS
NEUTRAL ATOM BEAM INJECTION
PLASMA
BEAM INJECTION
CHARGED PARTICLES
ELEMENTS
ENERGY-LEVEL TRANSITIONS
IONS
NONMETALS
640301* - Atomic
Molecular & Chemical Physics- Beams & their Reactions