Direct Energy Conversion (IV), Thermionic.

Abstract

The purpose of these notes is to present a partial Analysis of Thermionic
converter.
The basic phenomena of thermionic conversion IS divided in two classes ,
Emission phemomena and transport phenomena.
Practically thernionic conversion is a method for converting heat directly
into electricity through use of the thermionic emission.
A thermionic convertor consists of a heat source, two electrodes separated by
an intervening space, a heat sink and the leads connectng the electrodes to the
electrical load.
The electrodes are located in a highly evacuated enclosure, or in an
enclosure filled with a suitable rarefied vapor. In thermodynamics terminology
a thermionic converter is a heat engine operating in a cycle. There is a direct
analogy between a thermionic conveter and a simple vapor cycle engine.