Power deposition by mode converted electron Bernstein waves in the DIII-D `heat pinch' experiments

Mode converted electron Bernstein waves are shown to play an important role in power deposition in the off-axis electron cyclotron heating experiments on the DIII-D tokamak in which the effect known as the `heat pinch' was inferred. Ray tracing shows that the mode converted Bernstein modes (generated when the launched X mode reflects from an outboard upper hybrid layer) are damped in the central region where the previous transport analysis had assumed no power was being deposited.