Speaker
Description
The world is preparing designs for various forms of Fusion Pilot Plants (FPPs) that will demonstrate electricity delivered to the grid from a fusion reactor for the first time. While electron cyclotron (EC) technology is a relatively mature fusion technology, there will still be need for advancement to economically generate electricity in a power plant setting.
Dielectric lined waveguides are economic alternatives to corrugated waveguides that can operate at higher frequencies. Because a thin dielectric layer replaces the finely machined corrugations, the cost of fabricating high-tolerance waveguides can be driven down, and the operating frequency can extend well into the THz regime. GA has recently developed dielectric lined waveguides and tested them in high-power ECH conditions [1].
As the fusion industry matures, so too must our ability to characterize and test fusion technologies. EC waveguide testing currently requires large waveguide prototype assemblies and expensive high-power gyrotron tests. GA has demonstrated a low-power method for accurately characterizing loss in overmoded waveguide by turning a short waveguide into a Fabry-Pérot cavity using two dielectric mirror caps and measuring the resonant peak width [2].
FPPs will also naturally operate at higher power regimes where there’s a greater risk to diagnostics from stray EC radiation. Stray radiation waveguide power monitors must be able to detect damaging amounts of EC radiation to rapidly activate protection circuits for microwave-based diagnostics such as reflectometry and EC emissions. To this end, GA has developed a dual-polarized power monitor miter bend directional coupler to robustly detect stray EC radiation [3].
Funding Acknowledgements
The dielectric lined waveguide and Fabry-Pérot cavity works were supported by General Atomics internal research and development funding.
The Fabry-Pérot cavity work was also supported by the U.S. Department of Energy under the Science Undergraduate Laboratory Internship (SULI) program.
The project related to the EC radiation monitor was supported by US DOE Contract No. DE-AC02-09CH11466, and is managed by the US ITER Project Office, hosted by Oak Ridge National Laboratory with partner labs Princeton Plasma Physics Laboratory and Savannah River National Laboratory. The project is being accomplished through a collaboration of DOE Laboratories, universities and industry. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization.
References
[1] K.A. Thackston, M.P. Ross, J.P. Anderson, IAEA Fusion Energy Conference. CN-316. October 2023.
[2] K.A. Thackston, J. Doane, J.P. Anderson, M. Chrayteh, F. Hindle, J. Infrared, Millimeter, and Terahertz Waves, February 2023.
[3] C.M. Muscatello et al. 5th European Conference on Plasma Diagnostics. P3-20. April 2023.
