Electron Cyclotron Heating Systems and Modeling for the WHAM Device

The Wisconsin HTS Axisymmetric Mirror (WHAM) device will use 110 GHz Electron Cyclotron Heating (ECH) waves to generate the plasma through ECH breakdown as well as control and maintain the desired electron temperature profile. An overview of the ECH system in WHAM will be presented including the gyrotron system, the waveguide run and the launching structure. The current state of computational modeling for the ECH waves using the Genray ray tracing code and a custom particle and power balance program will also be discussed, with particular emphasis on how this combines with other heating systems to generate the desired plasma parameters and profiles. The focus will be on a high field side, fundamental X mode launch for which modeling shows >95% power absorption, however alternative launch scenarios which have shown up to 90% absorption under high density conditions are also examined. Lastly, initial results from gyrotron testing into burn paper will be shown.