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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 ÃÛÌÇÖ±²¥ 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.