Gyrotron FU CW VII for 300 MHz and 600 M

Gyrotron FU CW VII, part of the FU CW Series Gyrotrons, has been successfully designed and operationally tested at the Research Center for Development of Far Infrared Region at the University of Fukui. This gyrotron operates at approximately 200 GHz for fundamental cyclotron resonances and around 400 GHz for second harmonics, facilitating applications in 300 MHz and 600 MHz DNP enhanced NMR spectroscopy. The development of high frequency continuous wave (CW) gyrotrons is essential for high power THz technologies, as conventional radiation sources such as BWOs or TWTs fail to provide the necessary output power. Previous advancements have shown that short pulse gyrotrons can exceed 1 THz, but they often do not suffice for many applications requiring continuous operation. Subsequently, the FIR FU has focused on developing its CW gyrotron series, comprising six iterations to date, explicitly designed to meet the high power needs in THz technology applications, demonstrating their potential for DNP-NMR spectroscopy among other usages. The results provide a solid foundation for future explorations in high power THz technologies, reinforcing the critical role of gyrotrons in advancing these fields.