RESEARCH IS PROPOSED TO PERFORM INITIAL ACTIVITIES TOWARD ESTABLISHING THE FEASIBILITY AND PERFORMANCE RAMIFICATIONS OF EMPLOYING VERY HIGH TEMPERATURE THERMIONIC CONVERSION IN SPACE NUCLEAR POWER SYSTEMS OPERATING UNDER BURST POWER CONDITIONS.

RESEARCH IS PROPOSED TO PERFORM INITIAL ACTIVITIES TOWARD ESTABLISHING THE FEASIBILITY AND PERFORMANCE RAMIFICATIONS OF EMPLOYING VERY HIGH TEMPERATURE THERMIONIC CONVERSION IN SPACE NUCLEAR POWER SYSTEMS OPERATING UNDER BURST POWER CONDITIONS. SUCH REACTOR SYSTEMS ARE PRESENTLY UNDER ACTIVECONSIDERATION FOR DEVELOPMENT UNDER THE STRATEGIC DEFENCE INITIATIVE PROGRAM. THE DESIGN OF THE PREVIOUS IN-CORE THERMIONIC REACTOR CONCEPTS HAS BEEN DOMINATED BY THE NECESSITY TO ACHIEVE A HIGH DEGREE OF MATERIALS STABILITY INORDER TO OBTAIN A LONG-LIVED SYSTEM. FOR BURST-POWER APPLICATIONS, THIS CONSTRAINT IS MUCH LESS IMPORTANT AND THENEED IS TO ACHIEVE VERY HIGH CURRENT (POWER) DENSITIES WITHIN THE CORE, COMBINED WITH HIGH CONVERSION EFFICIENCY. ONE MEANS OF ACHIEVING HIGH POWER DENSITIES FOR SHORT TIME PERIODS IS TO INCREASE THE EMITTER TEMPERATURE TO 2400 K OR HIGHER, OPERATE THE CONVERTER IN THE UNIGNITED MODE, AND KEEP THE INTERELECTRODE CESIUM VAPOR AT LOW PRESSURE. AT PRESENT, ONLY THE RUSSIANS HAVE OPERATED CONVERTERS AT TEMPERATURES IN EXCESS OF 2400 K, AND THIS ONLY TO A VERY LIMITED DEGREE. THIS RESEARCH PROPOSES TO PERFORM PRELIMINARY ACTIVITIES ESSENTIAL TO ESTABLISHING THE TECHNICAL FEASIBILITY OF THE HIGH TEMPERATURE THERMIONIC REACTOR CONCEPT. PHASE I WILL RESULT IN CONCEPT FEASIBILITYEVALUATIONS AND PERFORMANCE ESTIMATES FOR THE CONVERTERS ANDFOR CONCEPTUAL BURST POWER REACTOR SYSTEM. THE ANTICIPATED PHASE II ACTIVITIES WOULD INCLUDE: 1. CONSTRUCTION OF A HIGH TEMPERATURE CONVERTER AND TEST STRAND. PROCUREMENT OF EMITTER MATERIALS IN THE REQUIRED GEOMETRY. 3. CONDUCT OF HIGH TEMPERATURE CONVERTER EXPERIMENTS, 4. CORRELATION WITH THEORY 5. EVALUATION OF RESULTS WITH REGARD TO THEIR CONSEQUENCES TO THE DESIGN OF A PRACTICAL BURST POWER SPACE NUCLEAR REACTOR SYSTEM.