Hydrogen vibrational population distributions and negative ion concentrations in a medium density hydrogen discharge

Journal Article · Sat May 01 00:00:00 EDT 1982 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.331166· OSTI ID:5651068

Hiskes, J R; Karo, A M; Bacal, M; Bruneteau, A M; Graham, W G

The vibrational population distribution for hydrogen molecules in a hydrogen discharge has been calculated taking into account electron collisional excitation, molecule-molecule, and wall collisional de-excitation processes. Electronic excitation processes include vibrational excitation by 1 eV thermal electrons acting through the intermediary of the negative ion resonances, and vibrational excitation caused by the radiative decay of higher singlet electronic states excited by a small population of 60 eV electrons in the discharge. The molecules are de-excited by molecular collisions transferring vibrational energy into translational energy, and by wall collisions. The distributions exhibit a plateau, or hump, in the central portion of the spectrum. The relative concentration of negative ions is calculated assuming dissociative attachment of the low temperature electrons to vibrationally excited, non-rotating molecules. The ratio of negative ions to electrons in the discharge is calculated to be of order 1% if the vibrational excitation survives no more than one wall collision, and of order 10% if the excitation survives ten collisions. The possibility is considered that the higher concentrations can be achieved with few wall collisions provided dissociative attachment occurs to highly rotating molecules.

• Research Organization: Lawrence Livermore National Laboratory, University of California, Livermore, California 94550
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5651068
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 53:5; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

640420* -- Fluid Physics-- Properties & Structure of Fluids-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANIONS
CHARGED PARTICLES
DATA
ELECTRIC DISCHARGES
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY LEVELS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EV RANGE
EXCITATION
EXCITED STATES
FERMIONS
HYDROGEN
INFORMATION
ION DENSITY
IONS
LEPTONS
MATHEMATICAL MODELS
MOLECULES
NONMETALS
NUMERICAL DATA
RESONANCE
THEORETICAL DATA
VIBRATIONAL STATES