SP-100 REACTOR APPLICATIONS-

THIS PROJECT IS TO DETERMINE THE PRACTICAL FEASIBILITY OF OPERATING SP-100-TYPE THERMIONIC FUEL ELEMENTS (TFES) IN AN ADVANCED SELF-PULSED MODE OF OPERATION. SUCH OPERATION CAN POTENTIALLY GREATLY INCREASE THE PERFORMANCE OF THE TFES. TO ACHIEVE THIS AT PRACTICAL POWER LEVELS, ELECTRODES HAVING AN EMISSION CURRENT CAPABILITY MUCH GREATER THAN THE OUTPUT CURRENT MUST BE USED BUT AT VERY LOW CESIUM PRESSURES. A PRELIMINAR EXPERIMENT WILL DEFINE THE CONDITIONS UNDER WHICH CESIUM OXIDE VAPOR CAN BE USED TO OBTAIN SUCH CURRENTS AT THE HIGH EMITTER TEMPERATURES AND LOW CESIUM PRESSURE REQUIRED. USING THESE CONDITIONS, THE OUTPUT CHARACTERISTICS DURING CONSTANT-CURRENT, SELF-PULSED OPERATION OF AN EXISTING PLANAR RESEARCH CONVERTER WILL BE MAPPED AS A FUNCTION OF THE DOMINANT EXPERI- MENTAL VARIABLES TO DETERMINE THE OPTIMUM CONDITIONS FOR SUCH OPERATION AND ITS CONTROL. BASED ON THESE RESULTS, THE PRACTICAL FEASIBILITY AND EFFICACY OF THE SELF-PULSED TFE FOR SP-100 APPLICATIONS WILL BE ESTIMATED, AND THE WORK REQUIRED IN PHASE II FOR ITS REDUCTION TO ENGINEERING PRACTICE WILL BE DEFINED.