10 MW L-Band Klystron for Accelerators

Advanced L-Band sources are required for the International Linear Collider (ILC) and other proposed accelerator systems. These sources must produce 10 MW of RF power at an efficiency of at least 40% with a beam voltage of 120 kV or lower. However, it is impractical to achieve the required efficiency with a conventional klystron. Therefore, this project will develop a 10 MW, 1.3 GHz, annular beam klystron (ABK). The annular beam minimizes space charge depression and impedance, enabling the low voltage required for the ILC. Like the sheet beam klystron, the ABK uses a thin beam located close to the drift tube walls but operates with lower risk, single mode cavities. In addition, the ABK is azimuthally symmetric, thereby reducing design and fabrication costs. It operates at essentially the same voltage as a multi-beam klystron but is far simpler. Commercial Applications and other Benefits as described by the awardee: The ABK¿s relatively low voltage and simple geometry would minimize fabrication and power supply costs over other distributed beam devices. Klystrons are used in many accelerators for research and medical applications, and for radar and communications in industry and national defense applications. In all of these applications, the ABK would be expected to offer a significant cost advantage.