Design and Evaluation of Antennae for Electron Cyclotron Emission Measurements on Large Toroidal Plasmas

Abstract

In previous electron cyclotron emission (ece) measurement systems, the antennae used to collect the radiation from the plasma and transmit it to the interferometers has in most cases comprised simply of overmoded light pipe close to the tokamak observation window. This crude arrangement has none the less proved adequate in most systems, primarily because the constraints on the directionality of present receiving systems are not very stringent, and because the length of waveguide runs used is relatively short (and consequently not very lossy).