A THOMSON-SCATTERING PLASMA DIAGNOSTIC FOR MATERIALS TESTING

THE NEXT GENERATION OF MAGNETIC FUSION RESEARCH MACHINES, SUCH AS THE INTERNATIONAL THERMONUCLEAR EXPERIMENTAL REACTOR, IMPOSES EXTRAORDINARY DEMANDS ON THE FIRST WALL MATERIALS IN THE VACUUM VESSEL AND ESPECIALLY THE DIVERTERS. THIS PHASE I EFFORT ADDRESSES THE DESIGN OF A THOMSON-SCATTERING- BASED PLASMA DIAGNOSTIC SUITABLE FOR MEASURING THE PLASMA CHARACTERISTICS NEAR BOUNDARY SURFACES. SUCH DIAGNOSTIC MEASUREMENTS ARE NEEDED TO INTERPRET THE RESULTS FROM TESTING CANDIDATE FIRST WALL/DIVERTER MATERIALS FOR THE NEXT GENERATION OF MAGNETIC CONFINEMENT NUCLEAR FUSION MACHINES. IN PHASE I, A CONCEPTUAL MECHANICAL DESIGN OF THE DIAGNOSTIC SYSTEM IS BEING PREPARED. THE MECHANICAL DESIGN IS BEING STUDIED TO MAINTAIN LASER BEAM ALIGNMENT, AND AN OPTICAL FEEDBACK POSITIONING SYSTEM IS BEING DESIGNED. THE EXPECTED EMISSION OF PLASMA LIGHT AS WELL AS ECONOMIC CONSIDERATIONS WILL BE STUDIED, TO DETERMINE WHETHER NEODYMIUM OR RUBY LASERS WOULD BE MORE APPROPRIATE.