Design Studies of Megawatt-Class Continuous-Wave Elliptic-BeamI Inductive Output Tubes

Conventional circular-beam klystrons and inductive output tubes (IOTs) are the technologies of choice for accelerators for physics research and applications. While a commercially-available, conventional, circular-beam IOT provides lower operating voltage, smaller size, and higher efficiency than a klystron, its output power is limited to several tens of kilowatts. This project will involve design studies aimed at delivering 200 kW cw and 1 MW cw at 350 MHz, and 1 MW cw at 704 MHz. Phase I will (1) conduct thermal and mechanical analyses of the grids of the proposed elliptic-beam IOTs; (2) conduct theoretical modeling and a concept design of gridded elliptic diodes with high compressions; (3) perform a concept design of highly-compressed elliptic-beam systems; and (4) perform a concept design of the proposed megawatt-class elliptic-beam IOTs. The proposed design studies will help establish the figure of merit of megawatt-class continuous-wave elliptic-beam IOTs. Commercial Applications and other Benefits as described by the awardee Elliptic-beam IOTs have the potential to replace conventional circular-beam klystrons, circular-beam IOTs, and possibly multi-beam high-order-mode (HOM) IOTs for accelerator applications requiring highly efficient high-power RF sources at or below 1.3 GHz. Furthermore, elliptic-beam IOTs have the potential to replace conventional circular-beam IOTs, which are widely used for television broadcasting.