A radiant energy to electrical power thermionic conversion system using a transducer structure with very closely spaced cathode and anode elements in a vacuum to minimize space charge buildup and to optimize cross transfer of electrons from cathode to anode. The materials chosen are for a high work function...http://www.google.com.au/patents/US4188571?utm_source=gb-gplus-sharePatent US4188571 - Radiant energy to electrical power conversion system
