CERAMIC INSULATORS FOR PULSED ELECTROTHERMAL DISCHARGES GTD-43

HIGH POWER ELECTROTHERMAL DISCHARGE TECHNOLOGY PROVIDES AN ATTRACTIVE APPROACH FOR ACCELERATING SDI KEW PROJECTILES AND FOR SDI SPACE PROPULSION. STORED ENERGY IS USED TO HEAT SUITABLE PLASMA MATERIALS IN A LARGE L/D TUBE ON MICROSECOND TIME SCALES, CREATING A HIGH PRESSURE,LOW MOLECULAR WEIGHT JET. REPETITIVE OPERATION OF THESE JETS REQUIRESDEVELOPMENT OF A HIGH STRESS INSULATOR, RESISTANT TO THERMAL SHOCK, AND SEVERAL CERAMIC MATERIALS ARE PARTICULARLY WELL SUITED FOR THIS PURPOSE. THIS EFFORT IDENTIFIES APPROPRIATE MATERIALS, DESIGNS INSULATOR ASSEMBLIES OF CERAMICS WITH OUTER COMPRESSIVE JACKETS, AND ASSEMBLES CERAMICS INTO THEIR JACKETS WITHOUT DAMAGE. CANDIDATE MATERIALS ARE ALPHA-SIC, AL2O3, SI3N4 AND HD CAST SIC, AND OTHER CANDIDATES WILL BE IDENTIFIED. THE INSULATOR ASSEMBLY WILL BE DESIGNED TO WITHSTAND 4-8 KILOBARS, A PRESSURE OF INTEREST FOR KEW HYPERVELOCITY GUNS. AN ASSEMBLY TOOL WILL BE FABRICATED TO AID IN SHRINK FIT ASSEMBLY OF COMPRESSIVE JACKETS AND CERAMIC LINERS. CERAMIC LINERS WILL BE ASSEMBLED IN THEIR JACKETS. WITH THESE STEPS COMPLETED, CERAMIC LINER TESTING CAN BE PERFORMED AT A PHASE II LEVEL.