A Two-stage injection-locked magnetron for accelerators with superconducting cavities

TL;DR

This paper proposes a two-stage injection-locked CW magnetron system designed to efficiently power superconducting cavities in particle accelerators, demonstrating promising experimental results for high-power RF applications.

Contribution

It introduces a novel two-stage injection-locked magnetron concept with experimental validation for accelerator RF power sources.

Findings

Achieved a 30-40 dB power/locking ratio in experiments.

Demonstrated stable operation at 1-10 ms pulse durations.

Validated the feasibility for accelerator applications.

Abstract

A concept for a two-stage injection-locked CW magnetron intended to drive Superconducting Cavities (SC) for intensity-frontier accelerators has been proposed. The concept considers two magnetrons in which the output power differs by 15-20 dB and the lower power magnetron being frequency-locked from an external source locks the higher power magnetron. The injection-locked two-stage CW magnetron can be used as an RF power source for Fermilab's Project-X to feed separately each of the 1.3 GHz SC of the 8 GeV pulsed linac. We expect output/locking power ratio of about 30-40 dB assuming operation in a pulsed mode with pulse duration of ~ 8 ms and repetition rate of 10 Hz. The experimental setup of a two-stage magnetron utilising CW, S-band, 1 kW tubes operating at pulse duration of 1-10 ms, and the obtained results are presented and discussed in this paper.