Status and Modeling of Electron Cyclotron Heating systems for the Wisconsin HTS Axisymmetric Mirror

The Wisconsin HTS Axisymmetric Mirror (WHAM) is a high-field magnetic mirror under construction at UW-Madison. This device will use Electron Cyclotron Heating (ECH) for a variety of functions including breakdown, reducing fast ion slowing down, and achieving an electron temperature greater than 750 eV. An overview of the ECH system in WHAM will be presented including the 1 MW, 110 GHz gyrotron system, the waveguide run, and a rotatable launching structure which will aim ECH at different radial locations in the plasma. The current state of modeling for ECH waves using the Genray ray tracing code and CQL3D Fokker Plank solver will also be discussed, with emphasis on how ECH can create different Te profiles and what effect this can have on MHD stability in a vortex confined mirror plasma. Further discussion will detail how ECH may draw out a high energy tail of electrons, the effects of such on stability, and the diagnostic signatures it may produce. The focus will be on a high field side, fundamental X mode launch for which modeling shows >95% absorption, however alternative launch scenarios with up to 90% absorption under high density conditions are also examined. Lastly, results from gyrotron testing into vacuum waveguide will be shown.