A New approach of equilibrium reconstruction for ITER

Imazawa, Ryota; Kawano, Yasunori; Kusama, Yoshinori

We have developed the new method for identifying the -profile from data, whose accuracy is determined in ITER, in order to assess the necessary measurement accuracy of the poloidal polarimeter. We have adopted the finite element method to calculate the ideal MHD equilibrium. Assuming that all measurement data has no error, we have shown the Importance of using the measurement data of the electron temperature, , and the ellipticity angle, , of the polarization state in the inductive operation scenario II (S2), and the non-inductive operation scenario IV (S4). is used to calculate the relativistic effect on the polarization state. When the relativistic effect has not been included in the -profile identification, the error of -profile identification has exceeded 7.7 and 15 in S2 and S4, respectively. is mainly related to the Cotton-Mouton effect, which is an obstacle in measurement of a pure Faraday effect. Taking into account reduced the error of -profile identification by 0.5 . Finally, we have assessed the necessary accuracy of the orientation angle, , and the ellipticity angle, . The polarimetric measurements with accuracy of have satisfied the measurement requirement for the -profile identification ( ) in case of that viewing chords are via both equatorial and upper ports.