Predicting ion charge state distributions of vacuum arc plasmas

Conference · Mon Apr 01 04:00:00 EST 1996

OSTI ID:273727

Anders, A ^[1]; Schulke, T ^[2]

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1. Lawrence Berkeley Lab., CA (United States)
2. Fraunhofer-Einrichtung fuer Werkstoffphysik und Schichttechnologie (IWS), Dresden (Germany)

Multiply charged ions are present in vacuum arc plasmas. The ions are produced at cathode spots, and their charge state distributions (CSDs) depend on the cathode material but only little on the arc current or other parameters as long as the current is relatively low and the anode is not actively involved in the plasma production. There are experimental data of ion CSDs available in the literature for 50 different cathode materials. The CSDs can be calculated based on the assumption that thermodynamic equilibrium is valid in the vicinity of the cathode spot, and the equilibrium CSDs `freeze` at a certain distance from the cathode spot (transition to a non-equilibrium plasma). Plasma temperatures and densities at the `freezing points` have been calculated, and, based on the existence of characteristic groups of elements in the Periodic Table, predictions of CSDs can be made for metallic elements which have not yet been used as cathode materials.

• Research Organization: Lawrence Berkeley Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 273727
• Report Number(s): LBL--37921; CONF-960723--5; ON: DE96013220
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACTINIUM
AMERICIUM
CALCULATION METHODS
CHARGE STATES
ELECTRIC ARCS
EUROPIUM
IONIZATION
LUTETIUM
MULTICHARGED IONS
NEPTUNIUM
PLASMA
PLUTONIUM
PROMETHIUM
PROTACTINIUM
RARE EARTHS
RECOMBINATION
REFRACTORIES
RHENIUM
RUTHENIUM
SODIUM
TECHNETIUM
TERBIUM