CERN's LEIR Digital LLRF : system overview and operational experience

The Low Energy Ion Ring (LEIR) is an accumulation and acceleration ring in the Large Hadron Collider (LHC) ion injector chain. After its successful start in 2005, it has been running in three operational campaigns. The LEIR low-level RF (LLRF) system is the first all-digital LLRF to operate in a CERN circular machine. Its capabilities include beam control tasks as well as dual-harmonic cavity voltage/phase servoing. All the system control parameters are fully configurable, remotely and inbetween cycles; extensive built-in observation capabilities and diagnostics are available. The system is flexible, powerful and extremely reliable. This paper outlines the main building blocks and operational features, along with results obtained during the first years of operation.