A BRIGHT SOURCE OF MULTIPLY-CHARGED HEAVY IONS

THIS RESEARCH AIMS TO DEVELOP AN IMPROVED SOURCE OF MULTIPLY-CHARGED IONS FOR HEAVY-ION INERTIAL FUSION AND OTHER APPLICATIONS THAT REQUIRE VERY HIGH BRIGHTNESS. A CONVENTIONAL GAS-DISCHARGE SOURCE IS PLANNED THAT DEPENDS ON THE COMBINATION OF TWO ADDITIONAL NOVEL FEATURES. FIRST, THE INITIAL DENSE HOT PLASMA GAS GENERATED FROM A HIGH PRESSURE MICROCAPILLARY DISCHARGE IS FURTHER HEATED BY A LASER TO PRODUCE HIGHER CHARGE STATES. SECOND, THE ION TEMPERATURE AT THE PLASMA EMITTER SURFACE IS REDUCED USING PLASMA EXPANSION. THIS ARRANGEMENT RESULTS IN LOW EFFECTIVE ION PERPENDICULAR TEMPERATURE (HUNDREDS OF DEGREES KELVIN) AND CAN PRODUCE A WIDE VARIETY OF IONS AT HIGH BRIGHTNESS. THE PHASE I INVESTIGATION IS QUANTITATIVELY EVALUATING (1) PERFORMANCE OF THE EXPANSION COOLED ION SOURCE, USING COMPUTER CALCULATIONS TO TAKE INTO ACCOUNT RADIATION TRAPPING, MULTIPLE-STEP IONIZATION, AND COLLISIONS WITH THE BACKGROUND GAS AND THE ELECTRONS; AND (2) LASER HEATING OF THE DISCHARGE PLASMA.