Krzysztof T. Pozniak

Fast data acquisition measurement system for plasma diagnostics using GEM detectors

This paper refers to measurement system for plasma diagnostics for tokamaks currently being developed. For the most of the GEM detector readout structures, large number of input channels is required to form a working measurement system. This constraint is especially important for two-dimensional GEM readout structures. Presented measurement system layout is a general model for further implementation. The system is based on fast serial gigabit links and PCI-Express interface for communication. The system can support up to 512 measurement channels, per each PCI-Express x16 slot. The system consists of several modules – PCI-Express 8-to-1 switch, Analog Front End, ADC Front End, and FPGA backplane boards. Implemented data processing algorithms enable fast raw data acquisition and real-time processing. The integration algorithms allow measurement system to cooperate with GEM detector working at high rates.

OMTF firmware overview

This paper describes firmware architecture of a new part of muon trigger system of the CMS detector – one of four detectors installed along LHC accelerator in CERN. Overlap Muon Track Finder (OMTF) is a new trigger subsystem designed to work in difficult barrel-endcap region of CMS detector. OMTF is designed to receive data from different detector types and process it to select 3 best muon candidates. These muon candidates are then forwarded to Global Muon Trigger (GMT). Performance requirements demanded usage of custom designed hardware. All the data reception and processing takes part in modern, large FPGA device. The IPBus module allows easy firmware control and diagnostics via Ethernet connection.

Modeling of serial data acquisition structure for GEM detector system in Matlab

This article presents method of modeling in Matlab hardware architecture dedicated for FPGA created by languages like VHDL or Verilog. Purposes of creating such type of model with its advantages and disadvantages are described. Rules presented in this article were exploited to create model of Serial Data Acquisition algorithm used in X-ray GEM detector system. Result were compared to real working model implemented in VHDL. After testing of basic structure, other two structures were modeled to see influence parameters of the structure on its behavior.

Data distribution and dispatching software for processing measurement data acquired with SXR GEM-based system

We present the concept of data distribution and dispatching software which is prepared for low latency and high throughput SXR measurement system developed by our group. Its scope includes handling data acquisition from multiple FPGA chips, execution of numerical algorithms with the use of multiple threads and post calculation storage and transfer. Data transfer to CPU side is done with usage of DMA via PCIe interface with specially developed Linux driver. This paper describes the need and details of discussed part of the system.

The methodology of development of real-time and high-throughput heterogeneous devices for plasma confinement fusion diagnostics

This paper discusses the model and the development methodology that was proposed in the implementation process of the heterogeneous system for the WEST thermal fusion reactor. The objective was to provide a systematic approach to provide a heterogeneous device to handle high-throughput workloads with low-latency for the WEST Soft X-Ray impurities diagnostic. The presented mechanism is dedicated to augment the system applicability to a wider area of instrumentation for high-scale physics experiments.

High voltage generator module for high energy physics experiments

This document was prepared to discuss the high voltage generator module which can be used to supply X-ray Gas Electron Multiplier (GEM) detector. Emphasis was placed on the description of the module’s hardware structure. Furthermore, the detector protecting mechanisms the against the damage have been presented and described.

Charge cluster identification for multidimensional GEM detector structures

The measurement system based on GEM - Gas Electron Multiplier detector - is developed for soft X-ray diagnostics of tokamak plasmas. The multi-channel setup is designed for estimation of the energy and the position distribution of an Xray source. The focal measuring issue is the charge cluster identification by its value and position estimation. The fast and accurate mode of the serial data acquisition is applied for the dynamic plasma diagnostics. The charge clusters are counted in the space determined by 2D position, charge value and time intervals. Radiation source characteristics are presented by histograms for a selected range of position, time intervals and cluster charge values corresponding to the energy spectra.

GEM-based plasma radiation diagnostics development: design aspects affecting its performance

The advanced Soft X-ray (SXR) diagnostics setup devoted to studies of the SXR plasma emissivity focusing on the energy range of tungsten emission lines is at the moment a highly relevant and important for ITER/DEMO as W became a plasmafacing material and, therefore, plasma contamination by W and W transport in the plasma must be understood and monitored. The Gas Electron Multiplier (GEM) based SXR radiation detecting system under development by our group with a spatial and energy-resolved photon detecting chamber may become such a diagnostic setup; however, many physical, technical and technological aspects must be taken into consideration. This work presents the results of preliminary tests and simulations of the research into the optimal design of the detector’s internal chamber. The study of the influence of different GEM foils on the properties and distribution of the electron avalanche as well as the effect of the high rate photon flux on GEM foil performance was performed. Effect of electrodes alignment allowed choosing the gap distances which maximize electron transmission was also examined. Finally, the optimal readout structure design was identified suitable to collect a total formed charge effectively.

Widely parameterizable high-level synthesis

In recent years, HLS compilers are gaining increasing popularity. This popularity is due to the fact that FPGA chips can achieve higher computing power than traditional CPUs in fine-grained algorithms. The greatest development of compilers were in recent years. Both commercial and open solutions are being developed. The most difficult part of compilers are algorithms responsible for converting code from a high high level of abstraction to low. In commercial solutions, these algorithms are closed as a black box and open solutions have implemented rather simple algorithms. The article presents an alternative, open solution of a high-level synthesis compiler (HLS) implemented in Python with its algorithms. The compiler, based on Pythons high-level functional description, generates a configuration that allows the creation of a given structure in the FPGA system during the synthesis process. The article describes the design methods, tools and implementation of the developed Python-VHDL compiler with examples of its use.

Object oriented hardware-software test bench for OMTF diagnosis

In this paper the object oriented hardware-software model and its sample implementation of diagnostics for the Overlap Muon Track Finder trigger for the CMS experiment in CERN is described. It presents realization of test-bench for control and diagnosis class of multichannel, distributed measurement systems based on FPGA chips. The test-bench fulfills requirements for system’s rapid changes, configurability and efficiency. This ability is very significant and desirable by expanded electronic systems. The solution described is a software model based on a method of address space management called the Component Internal Interface (CII). Establishment of stable link between hardware and software, as a purpose of designed and realized programming environment, is presented. The test-bench implementation and example of OMTF algorithm test is presented.