Cavity simulator and controller for VUV free electron laser SIMCON 2.1, part I: algorithms and SIMCON system

The paper describes integrated system of hardware controller and simulator of the resonant superconducting, narrowband niobium cavity, originally considered for the TTF and TESLA in DESY, Hamburg (now predicted for the VUV and X-Ray FEL). The controller bases on a programmable circuit Xilinx VirtexII V3000 embedded on a PCB XtremeDSP Development Kit by Nallatech. The FPGA circuit configuration was done in the VHDL language. The internal hardware multiplication components, present in Virtex II chips, were used, to improve the floating point calculation efficiency. The implementation was achieved of a device working in the real time, according to the demands of the LLRF control system for the TESLA Test Facility. The device under consideration will be referred to as superconducting cavity (SCCav) SIMCON throughout this work. The following components are described here in detail: functional layer, parameter programming, foundations of control of particular blocks and monitoring of the real time processes. This note is accompanied by the one describing the DOOCS interface for the described hardware system. The interface was prepared in DOOCS and in Windows. The hardware and software of SIMCON was tested in CHECIA. The results were presented. While giving all necessary technical details required to understand the work of the integrated hardware controller and simulator and to enable its practical copying, this document is a unity with other TESLA technical notes published by the same team on the subject. Modeling was omitted, as it is addressed in detail in the quoted references.