Operation of a microwave plasma source for electron heating and antenna testing

One of the major challenges for magnetic fusion is the interaction of the plasma with materials. Linear plasma-material interaction test stands can benefit from additional electron heating of the high-density source plasma to increase the total plasma heat flux at the target to better simulate fusion reactor conditions (10-20 MW/m$^{2}$). A microwave-based plasma experiment has begun at ORNL to study electron heating of over-dense plasmas and to provide a plasma environment for antenna testing. The plasma is generated by high-field launched whistler waves at 18 GHz to create a moderate-density plasma (n$_{e}$$\sim$10$^{18}$/m$^{3}$). Electron heating of the over-dense plasma is provided by either whistler waves or electron Bernstein waves at 6 GHz. In addition, a single strap mockup antenna, designed to operate at 40-50 MHz, is being constructed to study near-field plasma interactions. The antenna will be placed in the experiment's central vacuum chamber, which will act as an rf test facility.