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Abstract
A novel Dual Frequency Differential Phase reflectometer has been designed and built at the Oak Ridge National Laboratory (ORNL). This new device has been installed and tested on the Toroidal Fusion Test Reactor (TFTR) at the Princeton Plasma Physics Laboratory (PPPL) at Princeton, N.J. The intended purpose of this new reflectometer is to measure continuous edge density profiles in front of the Ion Cyclotron Resonant Heating (ICRH) antennas in TFTR. These density profiles are a key element in the study of the plasma edge and the effect of the ICRH power on the plasma edge.
The work done for the thesis involved the development, construction, testing, modeling, data taking and analysis of the ORNL Dual Frequency Differential Phase reflectometer for TFTR. Computer programs to model the propagation of the probing beams in the plasma were created. The modeling code provided important data and parameters for the design and construction of the new reflectometer. New techniques to reconstruct the density profile from the reflectometer phase data were developed, improved, and tested using the modeling code. The reflectometer was successfully installed and tested at TFTR. The first reflectometer data provided accurate density profiles for a wide range of plasma configurations and scenarios. New analysis techniques were developed to analyze the reflectometer data. Operation during ICRH showed that there was a small but detectable change on the density profile at the interfacing edge of the plasma with the ICRH antenna.
The idea of the Dual Frequency Differential Phase reflectometer showed to be an excellent method to measure the density at the edge of the plasma where other diagnostics can not work well. Important new results for analysis of the data were developed.
