Observations of Electron Cyclotron Emission on the PLT tokamak

Abstract

At the Wurzburg meeting, we reported the installation of an improved radiation collection optical system for the fast-scanning Michelson interferometer that is being used to observe the electron cyclotron emission (ECE) from the PLT tokamak (1). The purpose of this optical system was (a) to provide control over the field of view in the PLT plasma, and (b) to allow the coupling of radiation from a blackbody source to the Michelson to be as much like the plasma-Michelson coupling as possible, in an effort to make absolutely calibrated measurements of the ECE. During the Würzburg meeting, a carbon mirror was installed for us on the far wall of the PLT vacuum vessel so that it served as a viewing target for the optical system. This paper reports on (a) observations of the ECE entering the optical system in two orthogonal directions of polarization that were made following the installation of the viewing target, and (b) the degree of success that has been achieved in an effort to make absolutely calibrated measurements of the ECE spectrum.