RESEARCH ON CESIUM VAPOR.
Final rept., 1 May-30 Sep 63,
ELECTRO-OPTICAL SYSTEMS INC PASADENA CALIF
Pagination or Media Count:
The esults of absolute absorption measurements near the resonance levels in cesium vapor show that, for cesium pressure ranges of interest to high power density cesium vapor thermionic converters, the atomic resonance absorption at 8521 angstroms and 8943 angstroms is consider ably greater than previously indicated in the literature. In addition to the resonance absorption, molecular absorption bands in the vicinity of 7600 angstroms were found and are strong enough to furnish an additional significant source of energy input to the plasma of a cesium vapor thermionic converter. On the basis of this absorption spectra, an ionization mechanism has been hypothesized for the production of the dominant ionic specie for space charge neutralization in high pressure cesium vapor thermionic converter plasmas. The mechanism consists of cesium atoms first being excited to approximately the 1.45 ev level by resonance radiation from the emitter and subsequently colliding with other excited atoms to form the molecular cesium ion. The results of experiments are reported which indicate that in the presence of resonance radiation there is a definite enhancement of space charge limited currents due to the hypothesized formation of the cesium molecular ion as the neutralizing agent. Author