This article is an overview of what has been implemented in the process of development and testing the GEM detector based acquisition system in terms of post-processing algorithms. Information is given on mex functions for extended statistics collection, unified hex topology and optimized S-DAQ algorithm for splitting overlapped signals. Additional discussion on bottlenecks and major factors concerning optimization is presented.
This paper describes system for a diagnostics of a high-voltage power supply section of tokamaks. System is designed to assure reliability and safety of power supply subsystems. It is divided into two main components: remote and local. Remote part is located near tokamak, whereas local part can be localised away from the tokamak area. The remote side consists of custom, standalone devices. On the other hand, the local device is based on the uTCA.4 architecture. Components are connected with an optic fibre over a link-layer protocol which provides high throughput, low latency and transmission redundancy. All main operations ie. data processing, transmission etc. are performed on the FPGA devices. At the local side there is one device treated as a master device. It implements sort of a routing table which connects consecutive system inputs and outputs. It also provides possibility for some user defined data processing. This document contains general system overview, short description of hardware used in the project and gateware implementation.
Soft X-ray (SXR) measurement systems working in tokamaks or with laser generated plasma can expect high photon fluxes. Therefore it is necessary to focus on data processing algorithms to have the best possible efficiency in term of processed photon events per second. This paper refers to recently designed algorithm and data-flow for implementation of charge data acquisition in FPGA. The algorithms are currently on implementation stage for the soft X-ray diagnostics system. In this paper despite of the charge processing algorithm is also described general firmware overview, data storage methods and other key components of the measurement system. The simulation section presents algorithm performance and expected maximum photon rate.
This paper describes recently developed system for diagnostics of high-voltage power supply section of tokamaks’. Such system is necessary for real-time monitoring of high-voltage power supply section with ability to perform automatic and fast decisions related to protection system. The system is distributed, allowing data acquisition of components installed away from the systems’ controller. Remote communication is based on fiber links. Main processing units are FPGA circuits. The system can pass-through analog and digital signals from local to remote or remote to local locations. In the main FPGA unit, independent user developed algorithms can be implemented. The system structure is based on the uTCA standard. The micro TCA crate controller is implemented as PC unit in AMC standard. Communication is based on gigabit transceivers providing low-latency of data transmission. The system is working with specialized diagnostics and control software. The graphical user interface is provided for the end user. Several tests were made in term of data latency, proper signal transmission and system control.
This article debates about data fast acquisition and histogramming method for the X-ray GEM detector. The whole
process of histogramming is performed by FPGA chips (Spartan-6 series from Xilinx). The results of the histogramming
process are stored in an internal FPGA memory and then sent to PC. In PC data is merged and processed by MATLAB.
The structure of firmware functionality implemented in the FPGAs is described. Examples of test measurements and
results are presented.
The Triple Gas Electron Multiplier (T-GEM) is presented as soft X-ray (SXR) energy and position sensitive detector for high-resolution X-ray diagnostics of magnetic confinement fusion plasmas . Multi-channel measurement system and essential data processing for X-ray energy and position recognition is consider. Several modes of data acquisition are introduced depending on processing division for hardware and software components. Typical measuring issues aredeliberated for enhancement of data quality. Fundamental output characteristics are presented for one and two dimensional detector structure. Representative results for reference X-ray source and tokamak plasma are demonstrated.
A novel approach to two dimensional Gas Electron Multiplier (GEM) detector readout is presented. Unlike
commonly used methods, based on discriminators and analogue FIFOs, the method developed uses simulta-
neously sampling high speed ADCs with fast hybrid integrator and advanced FPGA-based processing logic to
estimate the energy of every single photon. Such a method is applied to every GEM strip / pixel signal. It is
especially useful in case of crystal-based spectrometers for soft X-rays, 2D imaging for plasma tomography and
all these applications where energy resolution of every single photon is required. For the purpose of the detector
readout, a novel, highly modular and extendable conception of the measurement platform was developed. It is
evolution of already deployed measurement system for JET Spectrometer.
This paper describes architecture of a new data acquisition system (DAQ) targeted mainly at plasma diagnostic experiments. Modular architecture, in combination with selected hardware components, allows for straightforward reconfiguration of the whole system, both offline and online. Main emphasis will be put into the implementation of data transmission subsystem in said system. One of the biggest advantages of described system is modular architecture with well defined boundaries between main components: analog frontend (AFE), digital backplane and acquisition/control software. Usage of a FPGA chips allows for a high flexibility in design of analog frontends, including ADC ↔ FPGA interface. Data transmission between backplane boards and user software was accomplished with the use of industry-standard PCI Express (PCIe) technology. PCIe implementation includes both FPGA firmware and Linux device driver. High flexibility of PCIe connections was accomplished due to use of configurable PCIe switch. Whenever it's possible, described DAQ system tries to make use of standard off-the-shelf (OTF) components, including typical x86 CPU & motherboard (acting as PCIe controller) and cabling.
This paper describes the concept of data management software for the multichannel readout system for the GEM
detector used in WEST Plasma experiment. The proposed system consists of three separate communication
channels: fast data channel, diagnostics channel, slow data channel. Fast data channel is provided by the FPGA
with integrated ARM cores providing direct readout data from Analog Front Ends through 10GbE with short,
guaranteed intervals. Slow data channel is provided by multiple, fast CPUs after data processing with detailed
readout data with use of GNU/Linux OS and appropriate software. Diagnostic channel provides detailed feedback
for control purposes.
This paper describes current status of electronics, firmware and software development for new plasma measurement
system for use in WEST facility. The system allows to perform two dimensional plasma visualization (in time) with
spectrum measurement. The analog front-end is connected to Gas Electron Multiplier detector (GEM detector).
The system architecture have high data throughput due to use of PCI-Express interface, Gigabit Transceivers and
sampling frequency of ADC integrated circuits. The hardware is based on several years of experience in building X-ray
spectrometer system for Joint European Torus (JET) facility. Data streaming is done using Artix7 FPGA devices.
The system in basic configuration can work with up to 256 channels, while the maximum number of measurement
channels is 2048. Advanced firmware for the FPGA is required in order to perform high speed data streaming and analog
signal sampling. Diagnostic system management has been developed in order to configure measurement system, perform
necessary calibration and prepare hardware for data acquisition.
Presented 2D gaseous detector system has been developed and designed to provide energy resolved fast dynamic plasma radiation imaging in the soft X-Ray region with 0.1 kHz exposure frequency for online, made in real time, data acquisition (DAQ) mode. The detection structure is based on triple Gas Electron Multiplier (GEM) amplification structure followed by the pixel readout electrode. The efficiency of detecting unit was adjusted for the radiation energy region of tungsten in high-temperature plasma, the main candidate for the plasma facing material for future thermonuclear reactors. Here we present preliminary laboratory results and detector parameters obtained for the developed system. The operational characteristics and conditions of the detector were designed to work in the X-Ray range of 2-17 keV. The detector linearity was checked using the fluorescence lines of different elements and was found to be sufficient for good photon energy reconstruction. Images of two sources through various screens were performed with an X-Ray laboratory source and 55Fe source showing a good imaging capability. Finally offline stream-handling data acquisition mode has been developed for the detecting system with timing down to the ADC sampling frequency rate (~13 ns), up to 2.5 MHz of exposure frequency, which could pave the way to invaluable physics information about plasma dynamics due to very good time resolving ability. Here we present results of studied spatial resolution and imaging properties of the detector for conditions of laboratory moderate counting rates and high gain.