Piotr Dominik Pucyk

Measurement and control of field in RF GUN at FLASH

The paper describes the hardware and software architecture of a control and measurement system for electromagnetic field stabilization inside the radio frequency electron gun, in FLASH experiment. A complete measurement path has been presented, including I and Q detectors and FPGA based, low latency digital controller. Algorithms used to stabilize the electromagnetic field have been presented as well as the software environment used to provide remote access to the control device. An input signal calibration procedure has been described as a crucial element of measurement process.

Decomposition of MATLAB script for FPGA implementation of real time simulation algorithms for LLRF system in European XFEL

The European XFEL project uses the LLRF system for stabilization of a vector sum of the RF field in 32 superconducting cavities. A dedicated, high performance photonics and electronics and software was built. To provide high system availability an appropriate test environment as well as diagnostics was designed. A real time simulation subsystem was designed which is based on dedicated electronics using FPGA technology and robust simulation models implemented in VHDL. The paper presents an architecture of the system framework which allows for easy and flexible conversion of MATLAB language structures directly into FPGA implementable grid of parameterized and simple DSP processors. The decomposition of MATLAB grammar was described as well as optimization process and FPGA implementation issues.

MatLab script to C code converter for embedded processors of FLASH LLRF control system

The low level RF control system (LLRF) of FEL serves for stabilization of the electromagnetic (EM) field in the superconducting niobium, resonant, microwave cavities and for controlling high power (MW) klystron. LLRF system of FLASH accelerator bases on FPGA technology and embedded microprocessors. Basic and auxiliary functions of the systems are listed as well as used algorithms for superconductive cavity parameters identification. These algorithms were prepared originally in Matlab. The main part of the paper presents implementation of the cavity parameters identification algorithm in a PowerPC processor embedded in the FPGA circuit VirtexIIPro. A construction of a very compact Matlab script converter to C code was presented, referred to as M2C. The application is designed specifically for embedded systems of very confined resources. The generated code is optimized for the weight. The code should be transferable between different hardware platforms. The converter generates a code for Linux and for stand-alone applications. Functional structure of the program was described and the way it is acting. FLEX and BIZON tools were used for construction of the converter. The paper concludes with an example of the M2C application to convert a complex identification algorithm for superconductive cavities in FLASH laser.