PROBE MEASUREMENTS IN A CESIUM PLASMA CONVERTER,
Abstract
Measurements of the properties of the plasma in the interelectrode space of both conventional and arc mode thermionic converters were obtained with coaxial electrostatic probes. In the high temperature cesium plasma present in the con verter, it was found that severe distortion of the probe current-voltage characteristic occurs due to extraneous current leakage to the probe and thermionic emission from the probe tip. By means of techniques previously reported, these distortions were eliminated by employing a coaxial-type probe. A comparison of probe in formation is made to models of both types of converter. In the conventional mode of oper ation the measured electron energy distribution is Maxwellian with a temperature of 0.18 ev which corresponds closely to the emitter tem perature of 0.12 ev. In the arc mode converter, probe studies indicate that the electron energy distribution is non-Maxwellian with two energy groups existing in the plasma. The high-energy group of electrons corresponds closely in energy to emitter electrons which were accelerated by potentials comparable to emitter sheath po tentials. The lower energy group corresponds to electrons which are essentially in equilibrium with the cesium vapor in the interelectrode space of the converter. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1963
- Accession Number
- AD0411474
Entities
People
- R.h. Bullis
- W.j. Wiegand
Organizations
- United Aircraft Corporation