Selective ECR heating of trapped/passing electrons in the W7-X stellarator

Using specific features of the magnetic equilibrium in the W7-X stellarator, ECRH scenarios with X2 and X3 modes are discussed. The aim is to explore the possibility of selective heating of the different classes of electrons, passing and trapped, by different RF beams with different frequencies, which can be launched from ports located in different crosssections of the device. Perspectives for this kind of experiments in W7-X are estimated numerically by coupling transport and ray tracing codes.