LOW TEMPERATURE CESIUM PLASMA CONVERTER

Journal Article · Sun Jul 01 04:00:00 EDT 1962 · Advan. Energy Conversion

OSTI ID:4729290

Stenzel, W; Bernstein, M

Measurements of space potentials, electron temperatures, electron concentrations, and electron energy distributions were made, with the aid of plane Langmuir probes by means of a pulsed technique developed by Waymouth, inside the discharge of low-temperature cesium plasma converters operating at an emitter temperature of 1500 un. Concent 85% K and a cesium temperature of 200 un. Concent 85% C. Data obtained at the center of the discharge showed electron temperatures of about 10,000 un. Concent 85% K, concentrations in excess of 10/ sup 12/ electrons per cm/sup 3/, and space potentials more than 1 v above the collector potential under normal operating conditions. The electron energy distributions were strictly Maxwellian. Adjustable probes were used to obtain variations of the parameters along the axis of the discharge. Their results showed that a virtual collector'' exists a short distance from the emitter surface whose potential is from 1.1-- 1.5 v above the collector potential with respect to the emitter. The potential curve then remains essentially flat within the main part of the discharge, the plasma region. The electron concentration has a sinusoidal variation, reaching a maximum near the center and having magnitudes between 10/sup 12/ and 10/sup 13/ electrons per cm/sup 3/. The electron energy distributions are Maxwellian in the center of the plasma, but exhibit an excess of high energy electrons near both electrodes. The electron temperature rises to a maximum above 10,000 un. Concent 85% K near the emitter and falls toward the collector. A simple physical picture of the discharge is developed, and it is shown that a one-step ionization process by the high energy tail of the electron distribution is sufficient to explain the degree of ionization required to maintain the discharge. Phenomena taking place at the collector surface are analyzed. One possible mechanism is developed which can lead to electron distributions of the same nature as is observed in front of the collector. This mechanism is also shown to aid in the explanation of the socalled Langmuir paradox.'' (auth)

• Research Organization: Ford Instrument Co., Long Island, N.Y.
• NSA Number: NSA-17-020619
• OSTI ID: 4729290
• Journal Information: Advan. Energy Conversion, Journal Name: Advan. Energy Conversion Vol. Vol: 2
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CESIUM
CONVERSION
DISTANCE
ELECTRIC DISCHARGES
ELECTRIC POTENTIAL
ELECTRON TEMPERATURE
ELECTRONS
EMISSION
ENERGY
IONIZATION
LANGMUIR PROBE
LOW TEMPERATURE
MAXWELL DISTRIBUTION
MEASURED VALUES
OPERATION
PHYSICS
PLASMA
PULSES
QUANTITY RATIO
SAMPLING
SPECTRA
SURFACES
TEMPERATURE
VARIATIONS