A Gallium Nitride-based Matchless Radio-Frequency Generator

Inductively coupled plasmas (ICPs) are replacing arc sources to increase the power and reliability of neutral beam systems used for plasma heating and control in fusion energy. ICPs are driven by a radio frequency (RF) generator that is impedance matched to the plasma. However, matching networks increase the cost, complexity, and thermal management requirements of ICPs, all of which scale with power of the RF generator. If the matching network could be eliminated, without impacting plasma performance, this would be a significant advantage for a new type of RF generator. Eagle Harbor Technologies, Inc. (EHT) is proposing to develop a new high-frequency (>10 MHz) RF generator that eliminates the matching network. This new generator will leverage EHT’s experience designing low-frequency RF generators and the latest wide-band gap solid-state switches. In the Phase I, EHT will design, build, and test a new high-frequency Matchless RF Generator. This generator will be kilowatt-class and reduce the technical risks of developing a higher power system in a potential Phase II program. Higher power systems are required for plasma sources for the neutral beam injection systems used in fusion energy. The proposed work will reduce the cost and complexity of RF generators needed for high-power ICPs in neutral beam systems for fusion energy. The initial beneficiaries are expected to be the universities and national laboratories, followed by privately-funded fusion companies, that use ICPs for their neutral beam sources, both domestic and international. In addition, this work will introduce a new type of RF generator to the semiconductor industry that will enable new applications in atomic layer etching, atomic layer deposition, and remote plasma sources, while reducing cost. The proposed work seeks to reduce the cost and complexity of power systems used for plasma generation in the fusion science and semiconductor industries.