Speaker
Description
RF cavity breakdowns present a limitation in high-gradient accelerators. Precise diagnostics are required to identify these breakdown events and potentially predict and mitigate them. These functions are critical for ensuring operational stability and preventing damage to the cavities from these events. This contribution presents the use of an optical fiber beam loss monitor, positioned along the beam line as a distributed sensor, optimized to localize breakdowns within the RF cavity.
The monitor uses Cherenkov radiation, which is produced when relativistic particles pass through the fiber. The sensor detects Cherenkov radiation from the breakdown-induced charge shower, which propagates bidirectionally to both fiber ends. Using time-of-arrival analysis of the signals received at each end of the fiber, the method can find differences in their timing to pinpoint the breakdown event location/time, potentially helping to identify breakdown hotspots rapidly. This technique has the advantages of being both non-invasive and scalable to any number of cavities, and the primary application is the development of a real-time RF breakdown diagnostic that can be used to monitor conditioning procedures and cavity performance.
Current experimental results demonstrate successful localization with an installation at CLARA (STFC, UK) during RF conditioning. The technique offers advantages over other breakdown detectors since it provides longitudinal coverage along the structure while operating with a single and non-invasive element. Future developments will focus on building real-time processing capabilities for the monitor and studying the implementation of machine learning techniques for classification or prediction of events, with the long-term goal of integrating the monitor into an operating accelerator and machine protection system.
