Author/Authors :
Michel، نويسنده , , Georg and Erckmann، نويسنده , , Volker and Hollmann، نويسنده , , Frank and Jonitz، نويسنده , , Lothar and Kasparek، نويسنده , , Walter and Laqua، نويسنده , , Heinrich and Lechte، نويسنده , , Carsten and Marushchenko، نويسنده , , Nikolai and Plaum، نويسنده , , Burkhard and Turkin، نويسنده , , Yuriy and Weiكgerber، نويسنده , , Michael، نويسنده ,
Abstract :
The polarization of the directed ECRH power has to be matched to the plasma boundary with respect to the magnetic field at the density gradient region close to the last closed flux surface (LCFS). This is achieved by means of grooved mirrors, which provide the required polarization and which are part of the matching optics unit (MOU) of the gyrotrons. The RF radiation from the gyrotrons has to pass typically 16 mirrors in a complex three-dimensional arrangement in order to reach the plasma. The paper discusses the modeling of the ECRH transmission in order to find the required polarizer adjustment for each possible injection angle and plasma wave type (O- or X-mode). This includes the calculation of the polarization state on the plasma boundary, the back-propagation through the transmission line up to the MOU and finally the calculation of the corresponding angles of both polarizers.
