Electron cyclotron emission imaging diagnostic system for Rijnhuizen Tokamak Project

A 16-channel electron cyclotron emission (ECE) imaging diagnostic system ha s been developed and installed on the Rijnhuizen Tokamak Project for measur ing plasma electron cyclotron emission with a temporal resolution of 2 mu s . The high spatial resolution of the system is achieved by utilizing a low cost linear mixer/receiver array. Unlike conventional ECE diagnostics, the sample volumes of the ECE imaging system are aligned vertically, and can be shifted across the plasma cross-section by varying the local oscillator fr equency, making possible 2D measurements of electron temperature profiles a nd fluctuations. The poloidal/radial wavenumber spectra and correlation len gths of T-e fluctuations in the plasma core can also be obtained by properl y positioning the focal plane of the imaging system. Due to these unique fe atures, ECE imaging is an ideal tool for plasma transport study. Technical details of the system are described, together with preliminary experimental results. (C) 1999 American Institute of Physics. [S0034-6748(99)69701-5].