Polarization and Mode Control of EAST 140 GHz ECRH&CD System

• DOI: 10.1007/s10894-014-9721-6
• Publication Date: 2014-05-31T17:56:37Z
• Authors: D. J. Wu; X. J. Wang; H. D. Xu; F. K. Liu; J. F. Shan; Y. Y. Tang; L. Xu; L. Y. Zhang; M. H. Li; W. Wei
• Keywords: Polarizer; Spherical tokamak; Neutral Beam Injection

The 140 GHz electron cyclotron heating and current drive (ECRH&CD) project was launched in 2011 on EAST tokamak facility, which is designed to launch 4 MW of total power for the duration up to 1,000 s into the plasma. The heating and current drive efficiencies depend on the wave coupling mode in plasma and the coupling performance relies on polarization characteristics of injected beam, so polarization control is necessary for efficient plasma heating and current drive. Two polarizer miter bends will be used to control the wave polarization for each transmission line on EAST ECRH&CD system, any required wave polarization can be produced by adjusting the mirror rotation angle of each polarizer miter bend. This work mainly shows the calculated polarizer mirror settings as a function of the injection angles for pure second extraordinary harmonic mode coupling.