Design of an X-mode swept frequency modulation reflectometer for the measurement of KSTAR plasma density profiles (invited)

Abstract

An X-mode swept frequency modulation (FM) reflectometry system has been designed to measure the electron density profiles of the "initial" KSTAR plasma. Fast swept HTO oscillators are employed to avoid density fluctuation effects, and frequency quadruplers are utilized to expand the HTO frequency range of 8-18 GHz to completely cover the X-mode cutoff frequency range of 33-66 GHz. The system can also be utilized to measure the edge profiles of the "Day One" KSTAR plasma by either switching from X- to O-mode reflectometry or by employing higher frequency millimeter-wave components and retaining the X-mode reflectometry configuration. To facilitate engineering design and optimization, a 3D drawing tool is utilized to effectively deal with any technical problems that may happen under actual KSTAR conditions. Details of the KSTAR FM reflectometry system are described together with important design issues. (C) 2004 American Institute of Physics.