The Impedance of a Resonance Probe†

Autor: D. L. Mckeown, R. L. Ferrari
Rok vydání: 1967
Předmět:
Zdroj: International Journal of Electronics. 23:39-68
ISSN: 1362-3060
0020-7217
DOI: 10.1080/00207216708961515
Popis: The solution of Laplace's equation for an electrically short cylindrical antenna by a finite-difference method is described. Numerical computations of the antenna impedance were carried out at various signal and collision frequencies and sheath thicknesses and the results are summarized graphically. A hot cathode, mercury arc discharge tube was constructed to produce electron densities greater than 108 electrons/cm3. Satisfactory agreement was found between measured and calculated probe impedances. It was found possible to determine the electron plasma frequency to within 8% of that obtained by Langmuir probe measurements. The effect of collapsing the ion sheath surrounding the probe was investigated. The effect of the radio frequency signal amplitude on the impedance characteristic of the probe was examined. Methods were developed to determine the resonant frequency rapidly. From this and a knowledge of the electron temperature it is shown that it is possible to estimate the electron plasma freq...
Databáze: OpenAIRE