New Trends in Microwave Imaging Diagnostics and Application to Burning Plasma

Microwave and millimeter-wave (mm-wave)-based diagnostics have proven invaluable in the understanding of magnetic confinement fusion plasma science and have found wide application at major fusion facilities, including DIII-D, EAST, ASDEX-U, HL-2A, KSTAR, and J-TEXT. This trend is expected to continue unabated in future burning plasma devices such as ITER and DEMO. Attractive features include their nonperturbing nature and relatively modest access requirements due to their short wavelength, as well as recent dramatic advances in the state of the technology. In this tutorial, we describe the basic principles of a number of microwave diagnostics measurements emphasizing imaging, recent technology advances including the so-called “system-on-chip (SoC)” technology, and “synthetic” diagnostics which simulate the response of diagnostics under actual experimental scenarios. The application of microwave diagnostics on reactor plasmas benefits immensely from the development of wide-bandgap electronics and advanced optics designs, both of which ameliorate the effects of the harsh environment.