DISCHARGE EFFECTS IN A CESIUM DIODE
Abstract
The feasibility of neutralizing the electron space charge in a cesium thermionic converter with ions formed by the collisions of electrons with neutral atoms was investigated. Equations were set up for the ion density and subsequent potential function for a low-pressure plasma in which the ions are formed by collisions of atoms with electrons emitted from the cathode with a Maxwellian velocity distribution. The special case of zero field at he emitter was taken to simplify the mathematics. Voltage-versus-current characteristics were determined experimentally for a cesium diode with a low work-function impregnated tungsten emitter operating at 1410 K and an electrode spacing of 0.254 cm. Cesium vapor pressures corresponding to condensation temperatures of 30 C, 100 C, and 155 C were used. The results indicated that higher cesium pressures, leading to more dense plasmas and successive collisions between electrons and excited atoms, are needed for complete spacecharge neutralization. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 15, 1962
- Accession Number
- AD0284678
Entities
People
- James Lawson Coggins
Organizations
- Massachusetts Institute of Technology