A HIGH THRUST DENSITY, C60 CLUSTER, ION THRUSTER

HIGH INTERGRID SPACE CHARGE LIMITS THE THRUST DENSITY OF AN ION ENGINE TO THE EXTENT THAT THESE THRUSTERS ARE PRESENTLY PRACTICAL FOR LIMITED NUMBER OF MISSIONS. BY REPLACING THE CURRENT PROPELLANTS OF CHOICE (XE, HG) WITH A CARBON CLUSTER PRPELLANT, CALLED FULLERENE, THIS DISADVANTAGE IS LARGELY ELIMINATED. FULLERENCE, C60, IS A RECENTLY DISCOVERED FORM OF CARBON THAT HAS MASS, STABILITY, AND LOW IONIZATION POTENTIAL THAT MAKE IT AN EXCELLENT CANDIDATE FOR AN ION THRUSTER FUEL. A C60 ION THRUSTER COULD PROVIDE UP TO A FACTOR OF 30, INCREASE IN THRUST DENSITY OVER THE CURRENT PROPELLANTS AND A SIMULTANEOUS RELATIVE LOSS REDUCTION BY A FACTOR OF 55. THE HIGH THRUST DENSITY CAUSES A REDUCTION IN REQUIRED ACCELERATOR GRID AREAS TO A SIZE THAT IS PRACTICAL EVEN FOR LARGE MEGAWATT SIZE THRUSTERS. THE OBJECTIVE OF THE PHASE I EFFORT IS TO PROVIDE ANSWERS FOR THE KEY C60 ION THRUSTER FEASIBILITY ISSUES. THE FULLERENES WILL BE EVAPORATED, IONIZED AND ACCELERATED IN A SMALL SCALE LOW COST EXPERIMENT. SUPPORTING ANALYTICAL WORK WILL PROCEED CONCURRENTLY. THE ISSUES THAT WILL BE ADDRESSED INCLUDE VAPOR GENERATION, ELECTRODE POISONING, IONIZATION, FRAGMENTATION AND ION ACCELERATION. DURING PHASE II, A PROTOTYPE C60 THRUSTER WILL BE DESIGNED AND CONSTRUCTED.