Fusion Science and Technology / Volume 59 / Number 4 / May 2011 / Pages 647-650
Technical Paper / Sixteenth Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating (EC-16)
Work has been done to assess the ability of electron cyclotron emission (ECE) measurements to resolve rotating magnetohydrodynamic (MHD) islands in the high-temperature plasmas of ITER. In ITER discharges the high electron temperature will cause relativistic broadening of ECE frequencies, significantly larger than experienced in current magnetic fusion devices. The broadening will result in spatial averaging of measured Te oscillations and hence a reduction of resolution. This effect is quantified by using a code that calculates the EC absorption and emission for an ITER scenario, and by using simulated Te data the reduction in amplitude is determined. It is found that the reduction is modest and that it should be possible to measure MHD islands of 1 cm and larger.