Wendelstein 7-X is an optimised stellarator designed for steady-state operation. The only steadystate capable heating system is electron cyclotron resonance heating (ECRH) launching microwaves at 140GHz into the vessel corresponding to the 2nd harmonic of the electron cyclotron frequency at 2.5 T. A quasi optical transmission line is used to bring the power into the machine. The power is launch...

Experiments are performed in the Large Plasma Device ~LaPD! @Gekelman et al., Rev. Sci. Instrum. 62, 2875 ~1991!# at the University of California, Los Angeles to study the propagation of the shear Alfvén wave in a parallel gradient of the background magnetic field. The waves are excited by modulating a field-aligned electron current drawn to a disk antenna with a radius on the order of the elec...

A method for self consistent calculations of ion cyclotron resonance heating has been developed. The dielectric tensor is calculated from a particle distribution function calculated with the orbit averaged Monte Carlo code fido. The tensor is then fed into the global wave code lion. The calculated wave field and power partitions are fed back into the fido code. By using two existing codes in an...

Abstract Energetic electron populations can substantially modify the neoclassical transport properties in stellarators. A model accounting for this change in transport is developed assuming the presence of electron cyclotron resonance heating (ECRH). The quasilinear diffusion coefficient for second harmonic X-mode ECRH is developed for a bumpy stellarator. Care is taken in accounting for the pi...

Kohn's theorem [1] is no longer applicable to multi-component systems, which consist of more than two kinds of electrons with di erent cyclotron frequencies. In such systems, cyclotron resonance (CR) is generally modi ed by electron-electron interaction in its positions and lineshapes. In this paper, interaction e ects on two-component CR is studied in asymmetric double quantum well (QW) system...