STUDIES OF PLASMA OSCILLATIONS. Quarterly Status Report No. 8, September 1-November 30, 1961

Technical Report · Tue May 01 04:00:00 EDT 1962

OSTI ID:4749411

The principle of measuring the number density of plasma by its proportionality to plasma frequency is explained. Two methods of calibration are described. One uses the output signal of the detector plotted versus the tubes d- c current and yields the average fluctuation in density as a proportionality involving the resonant frequencies associated with the d-c currents. The other method involves placing a low frequency a-c signal in series with the d-c power supply, producing a small a-c current in the tube and changing the plasma density. By proper calibration the ratio of change in number density ( DELTA n) to d-c number density (n/sub o/) is derived as ratios of a-c number density or current to d-c number density or current. Measurements by the second method were used to plot DELTA n/n/sub o/ along a mercury plasma column. Near the cathode variations in number density greater than 25% were found. Measurements of light output as a function of distance along the tube showed the nature of light output to be similar to the a-c density. Light output was also observed to be a maximum when a-c voltage was a minimum, indicating a possible 180 deg change in voltage phase in this region. (D.C.W.)

• Research Organization: Stanford Univ., Calif. Microwave Lab.
• NSA Number: NSA-17-015351
• OSTI ID: 4749411
• Report Number(s): TID-16057; ML-919
• Country of Publication: United States
• Language: English

Related Subjects

CATHODES
CONFIGURATION
CURRENTS
DENSITY
DETECTION
ELECTRIC POTENTIAL
EMISSION
FREQUENCY
LIGHT
MEASURED VALUES
MERCURY
OSCILLATIONS
PHYSICS
PLASMA
POWER PLANTS
RESONANCE
SIGNALS
STANDARDS
TUBES
VARIATIONS