Millimeter-Wave Diagnostic Systems for ITER

Abstract

To date, reliable measurements of electron temperature fluctuations in major tokamak experiments have remained elusive. Since electron heat transport in tokamaks is anomalously large, and appears to be driven by turbulent fluctuations, measuring spatially resolved electron and density temperature fluctuations is key to understanding both transport and the resultant turbulent confinement. Reflectometry has shown itself to be extremely sensitive to density fluctuations, and is a proven technique for making accurate electron density profiles. Electron cyclotron emission (ECE) imaging is a method whereby 2-D images of large amplitude coherent temperature fluctuations as well as 2-D electron temperature profiles of tokamak plasmas may be obtained. In this paper, we discuss the present status of each of these UC Davis diagnostic research areas, with particular emphasis on how the diagnostics may best be implemented on ITER.