Digital RF stabilization system based on MicroTCA technology

This article presents a generic digital control system for the stabilization of Radio Frequency (RF) fields used in particle accelerators, the Libera LLRF. Low Level RF (LLRF) systems have an important contribution in the overall performance of the accelerator since they are responsible for the control of amplitude and phase of electromagnetic fields inside the accelerating structures. The goal was to develop a high performance, small form factor system that uses the latest advances in technology. In order to fulfill these design goals Micro Telecommunications Computing Architecture (MicroTCA) and related standards were chosen as a basis for the system's hardware and software development. Results of hardware development are three different types of Advanced Mezzanine Cards (AMC), Interconnection Board (ICB), chassis, backplane and replaceable fan modules. The AMC boards are LLRF application specific and have input/output ports for RF signals. In order to enable support for different RF frequencies, they also include replaceable RF circuits. The ICB implements the functions of a MicroTCA Carrier Hub (MCH) and acts as a COM Express carrier board for the mounted COM Express module. With its different ports at the front, the ICB enables local and remote operation and maintenance of the Libera LLRF. Chassis management is implemented according to the Intelligent Platform Management Interface (IPMI) protocol. The LLRF application software, which runs on the Linux operating system and includes a Graphical User Interface (GUI), enables the user to operate the system and monitor different types of RF signals.