Recent radio frequency experiments in TFTR

Abstract

Recent experiments and theory have fueled renewed interest in Ion Bernstein Waves (IBW) in tokamaks. A direct launch IBW antenna was used for the first time on the Tokamak Fusion Test Reactor (TFTR), and Deuterium-Tritium Mode Conversion of fast waves to IBW has been demonstrated for the first time on TFTR. An estimated 20−40% of the launched RF power was coupled to the core of the plasma during the direct launch IBW coupling experiments. The initial demonstration of D-T MCCD in 1996 suffered from significant damping from Li7 minority heating. In 1997, Li6 was used to condition the walls of TFTR to avoid the presence of Li7, and efficient heating was observed. In addition, fast wave experiments were performed to test the ITER start up plasma scenario, and direct electron heating was tested for application in reversed shear plasmas.