State of the art high intensity proton accelerators require the development of an affordable cost, reliable RF sources with phase stability of less than 1 degree and amplitude control of +/- 15% (for identical cavities; in real situation the range can be wider). These power sources feed superconducting RF cavities for linacs capable of accelerating protons and ions up to several GeV.

A two-stage frequency-locked magnetron RF source will be developed to feed individual superconducting cavities. The 30-40 db gain of the system will be obtained by cascade operation of the magnetron stages controlled by slowly-varying phase generated by a Low Level RF (LLRF) system to damp electronically instabilities caused by microphonics.

Phase I successfully demonstrated phase and frequency stability of both a single injection-locked magnetron and a two stage (cascade) injection-locked magnetron system based on low-power (up to 1 kW) commercial CW magnetrons, operating in a pulsed mode (4.8-8ms pulse duration). The level of stability achieved shows that magnetron based RF sources are a feasible technology satisfying the requirements needed to drive superconducting RF cavities for Project X.
Phase II will demonstrate operation of the 2-stage (cascade) magnetron in full scale of power (tens kW) required for the Project X. Demonstration of the fast power control required for superconducting cavities will be performed. The required phase stability of the frequency-locked 2-stage magnetron will be achieved by electronic control with a Low Level RF system

If this project is successful, SRF linacs will have an option for potentially lower cost, high- efficient RF sources. Other related SRF linac applications such as accelerator-driven sub-critical reactors for power generation and the burning of nuclear waste will also be more affordable.