HIGH-BETA HOT-ELECTRON SURFACE-LAYER ENHANCEMENT OF CONFINEMENT IN STELLARATORS

THIS PROJECT WILL ASSESS THE FEASIBILITY OF ENHANCING THE PERFORMANCE OF TOROIDAL DEVICES FOR MAGNETIC CONFINEMENT OF FUSION PLASMAS BY USING HIGH-BETA, HOT-ELECTRON, SURFACE- LAYER PLASMAS. THE OBJECTIVE OF THIS ENHANCEMENT IS TO PERMIT STABLE OPERATION AT SUBSTANTIALLY HIGHER VALUES OF BETA THAN CAN BE ACHIEVED WITHOUT THE HOT-ELECTRON LAYER. IN PARTICULAR, THIS WORK WILL ADDRESS KEY QUESTIONS REGARDING THE APPLICATION OF ELECTRON CYCLOTRON HEATING (ECH) TO CREATE AND MAINTAIN THE HOT-ELECTRON LAYER. THIS WILL INCLUDE STUDYING WAYS OF MAXIMIZING THE HOT-ELECTRON PRESSURE WITHIN THE MINIMUM SURFACE-LAYER VOLUME CONSISTENT WITH REQUIREMENTS FOR PLASMA STABILITY. THE TECHNICAL APPROACH ADVOCATED IN THIS PROPOSAL IS AN EXTENSION OF WORK CARRIED OUT BY THE PRINCIPAL INVESTIGATORS OVER THE PAST TWO DECADES IN MAGNETIC MIRROR AND ELMO BUMPY TORUS DEVICES.SPECIFIC TOROIDAL CONFIGURATIONS TO BE INVESTIGATED INCLUDE STELLARATORS AND OTHER HELICAL MAGNETIC PLASMA CONFINEMENT CONCEPTS SUCH AS THE HELIAC.