Technical Concepts for Megawatt-Class Fusion Gyrotrons Operating at the Second Harmonic of the Cyclotron Frequency

In the frame of a EUROfusion Enabling Research (ENR) Project, KIT and NKUA have been working on new technical concepts for highly efficient, megawatt-class fusion gyrotron systems that will operate at the 2^nd-harmonic of the electron cyclotron frequency. This will reduce the required magnetic flux density in the gyrotron cavity by a factor of two and therefore will lead to more compact and cost-efficient gyrotron systems at DEMO-relevant and sub-THz frequencies.