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Overview

The "Impact Plasmas and Cosmic Dust Studies" Group is working on a number of projects based on measurement and assessment of turbulence and cross-field transport in magnetically confined plasmas. This research program combines local experiments at ¶¶ÒõÂÃÐÐÉä with collaborations among universities and national laboratories.

Diagnostic development work involves an ongoing collaboration with PPPL, U.C. Davis, and the FOM Institute in the Netherlands to develop a new microwave imaging instrument for simultaneous density and temperature fluctuation measurements in tokamaks. The instrument is a combined Electron Cyclotron Emission Imaging (ECEI) and Microwave Imaging Reflectometer (MIR) system, and is installed on the TEXTOR tokamak. Both subsystems use a shared set of large microwave optics to image the emitting/reflecting layer onto an array of detectors to provide high-resolution, time-resolved measurements.

Additional data analysis work by the group includes collaboration with the NSTX spherical torus at PPPL. This work involves the derivation of velocity field maps from time-dependent image sequences produced by the Gas Puff Imaging instrument. This is a diagnostic system which records light emission from the edge of tokamak plasmas with high spatial and temporal resolution. The velocity-field analysis reveals the dynamics of intermittent structures visible at the plasma periphery.