Diagnostics for the Rijnhuizen Tokamak Project

The research program of the Rijnhuizen Tokamak Project is concentrated on the study of plasma transport processes. The RTP tokamak is therefore equipped with an extensive set of multichannel diagnostics, including a 19-channel FIR interferometer, a 20-channel heterodyne ECE system, an 80-channel X-ray as well as an 80-channel visible light tomography system and a 30- to 60-channel Thomson-scattering system. The diagnostic set will soon be extended with a 19-channel FIR polarimeter, a 20-channel heterodyne ECA system and a multichannel pulsed radar system. Important new insights in some plasma physical phenomena have been obtained by combining data measured simultaneously with the various diagnostics. Some examples will be briefly presented: the effect of localized ECR heating on the electron density, the observation of density and temperature gradients in m = 2 magnetic islands as well as evidence for purely conductive local cooling prior to the energy quench phase of major disruptions.