Improved Magnetron Stability And Reduced Noise In Efficient Transmitters For Superconducting Accelerators

TL;DR

This paper investigates how controlling signals affect the stability, noise, and efficiency of magnetron transmitters used in superconducting accelerators, supported by experiments and an analytical model.

Contribution

It presents experimental validation of an analytical model for controlled magnetrons, demonstrating improved stability and reduced noise in RF sources for accelerators.

Findings

Controlled magnetrons show enhanced stability.

Noise levels are reduced with the proposed control methods.

The analytical model accurately predicts magnetron behavior.

Abstract

State of the art high-current superconducting accelerators require efficient RF sources with a fast dynamic phase and power control. This allows for compensation of the phase and amplitude deviations of the accelerating voltage in the Superconducting RF (SRF) cavities caused by microphonics, etc. Efficient magnetron transmitters with fast phase and power control are attractive RF sources for this application. They are more cost effective than traditional RF sources such as klystrons, IOTs and solid-state amplifiers used with large scale accelerator projects. However, unlike traditional RF sources, controlled magnetrons operate as forced oscillators. Study of the impact of the controlling signal on magnetron stability, noise and efficiency is therefore important. This paper discusses experiments with 2.45 GHz, 1 kW tubes and verifies our analytical model which is based on the charge drift approximation.