At present, conventional circular-beam klystrons and inductive output tubes (IOTs) are the technologies of choice for accelerators in physics research applications. While a 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 develop an innovative elliptic beam IOT to meet the requirement for a 140 kW peak power, 10% duty 402.5 MHz IOT. It is anticipated that the elliptic-beam IOT will overcome the current IOT power limitation, and that the efficiency will be even higher than that of the conventional circular-beam IOT, which is about 70%. Phase I will involve (1) theoretical modeling and concept design of a gridded elliptic diode; (2) concept design of the elliptic-beam system; and (3) concept design of the proposed elliptic-beam IOT. In Phase II the engineering design will be completed, and the proposed elliptic-beam IOT will be fabricated and tested. Commercial Applications and other Benefits as described by the awardeeIf successful, the technology should lead to a new class of higher efficiency IOTs, capable of extending the reach of IOTs into higher power territory which, at present, is dominated by klystrons that are more expensive and less efficient. Users of elliptic-beam IOTs should come from not only the physics accelerator community but also from the high-power digital television broadcast community, where IOTs have been widely used
