Design and implementation of universal mathematical library supporting algorithm development for FPGA based systems in high energy physics experiments

The X-ray free-electron laser XFEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short Xray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new perspectives for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated for LLRF system in VUV FEL experiment based on modern FPGA chips It is being developed by ELHEP group in Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller for stabilizing the vector sum of fields in cavities of one cryomodule in the experiment. The device can be also used as the simulator of the cavity and testbench for other devices. Flexibility and computation power of this device allow implementation of fast mathematical algorithms. This paper describes the concept, implementation and tests of universal mathematical library for FPGA algorithm implemetation. It consists of many usetill components such as IQ demodulator, division block, libra1y for complex and floating point operations, etc. It is able to speed up implementation time of many complicated algorithms. Library have already been tested using real accelerator signals and the performance achieved is satisfactory

An Evolutionary Approach to the Design of Controllable Cellular Automata Structure for Random Number Generation

Cellular Automata (CA) has been used in pseudorandom number generation over a decade. Recent studies show that two-dimensional (2-d) CA Pseudorandom Number Generators (PRNGs) may generate better random sequences than conventional one-dimensional (1-d) CA PRNGs, but they are more complex to implement in hardware than 1-d CA PRNGs. In this paper, we propose a new class of 1-d CA Controllable Cellular Automata (CCA) without much deviation from the structure simplicity of conventional 1-d CA. We give a general definition of CCA first and then introduce two types of CCA – CCA0 and CCA2. Our initial study on them shows that these two CCA PRNGs have better randomness quality than conventional 1-d CA PRNGs but their randomness is affected by their structures. To find good CCA0/CCA2 structures for pseudorandom number generation, we evolve them using the Evolutionary Multi-Objective Optimization (EMOO) techniques. Three different algorithms are presented in this paper. One makes use of an aggregation function; the other two are based on the Vector Evaluated Genetic Algorithm (VEGA). Evolution results show that these three algorithms all perform well. Applying a set of randomness tests on the evolved CCA PRNGs, we demonstrate that their randomness is better than that of 1-d CA PRNGs and can be comparable to that of two-dimensional CA PRNGs

FPGA Based, DSP Integrated, 8-Channel SIMCON, ver. 3.0. Initial Results for 8-Channel Algorithm

The paper describes design, construction and initial measurements of an eight channelelectronic LLRF device predicted for building of the control system for the VUV-FELaccelerator at DESY (Hamburg). The device, referred in the paper to as the SIMCON 3.0 (fromthe SC cavity simulator and controller) consists of a 16 layer, VME size, PCB, a large FPGAchip (VirtexII-4000 by Xilinx), eight fast ADCs and four DACs (by Analog Devices). To ourknowledge, the proposed device is the first of this kind for the accelerator technology in whichthere was achieved (the FPGA based) DSP latency below 200 ns. With the optimized datatransmission system, the overall LLRF system latency can be as low as 500 ns. The SIMCON3.0 sub-system was applied for initial tests with the ACC1 module of the VUV FEL accelerator(eight channels) and with the CHECHIA test stand (single channel), both at the DESY. Thepromising results with the SIMCON 3.0. encouraged us to enter the design of SIMCON 3.1.possessing 10 measurement and control channels and some additional features to be reported inthe next technical note. SIMCON 3.0. is a modular solution, while SIMCON 3.1. will be anintegrated board of the all-in-one type. Two design approaches - modular and all-in-one, afterbranching off in this version of the Simcon, will be continued

FPGA-Based Implementation of an Adaptive Noise Controller for Continuous Wave Superconducting Cavity

Low-level radio frequency (LLRF) systems have been designed to regulate the accelerator field in the cavity; these systems have been used in the free electron laser (FLASH) and European X-ray free-electron laser (E-XFEL). However, the reliable operation of these cavities is often hindered by two primary sources of noise and disturbances: Lorentz force detuning (LFD) and mechanical vibrations, commonly known as microphonics.This article presents an innovative solution in the form of a narrowband active noise controller (NANC) designed to compensate for the narrowband mechanical noise generated by certain supporting machines, such as vacuum pumps and helium pressure vibrations. To identify the adaptive filter coefficients in the NANC method, a least mean square (LMS) algorithm is put forward. Furthermore, a variable step size (VSS) method is proposed to estimate the adaptive filter coefficients based on changes in microphonics, ultimately compensating for their effects on the cryomodule. The proposed NANC method is characterized by low computational complexity, stability, and high tracking ability. By addressing the challenges associated with noise and disturbances in cavity operation, this research contributes to the enhanced performance and reliability of LLRF systems in particle accelerators