Advanced real-time evaluation and data quality monitoring model integration with FPGAs for tokamak high-performance soft X-ray diagnostic system

Based on the publications regarding new or recent measurement systems for the tokamak plasma experiments, it can be found that the monitoring and quality validation of input signals for the computation stage is done in different, often simple, ways. In the paper is described the unique approach to implement the novel evaluation and data quality monitoring (EDQM) model for use in various measurement systems. The adaptation of the model is made for the GEM-based soft X-ray measurement system FPGA-based. The EDQM elements has been connected to the base firmware using PCI-E DMA real-time data streaming with minimal modification. As additional storage, on-board DDR3 memory has been used. Description of implemented elements is provided, along with designed data processing tools and advanced simulation environment based on Questa software

Software Layer For FPGA-based Tesla Cavity Control System (part I)

The paper describes design and practical realization of software for laboratory purposes to control FPGA-based photonic and electronic equipment. There is presented a universal solution for all relevant devices with FPGA chips and gigabit optical links. The paper describes architecture of the software layers and program solutions of hardware communication based on Internal Interface (II) technology. Such a solution was used for superconducting Cavity Controller and Simulator (SIMCON) for the TESLA experiment in DESY (Hamburg). A number of practical examples of the software solutions for the SIMCON system were given in this paper

Zero-Suppression Trigger Mode for GEM detector measurement system

A novel approach to a trigger mode in the GasElectron Multiplier (GEM) detector readout system is presented.The system is already installed at WEST tokamak. The articlebriefly describes the architecture of the GEM detector and themeasurement system. Currently the system can work in twotrigger modes: Global Trigger and Local Trigger. All trigger processingblocks are parts of the Charge Signal Sequencer modulewhich is responsible for transferring data to the PC. Therefore,the article presents structure of the Sequencer with details aboutbasic blocks, theirs functionality and output data configuration.The Sequencer with the trigger algorithms is implemented inan FPGA chip from Xilinx. Global Trigger, which is a defaultmode for the system, is not efficient and has limitations due tostoring much data without any information. Local trigger whichis under tests, removes data redundancy and is constructed tosend only valid data, but the rest of the software, especially on thePC side, is still under development. Therefore authors proposethe trigger mode which combines functionality of two existingmodes. The proposed trigger, called Zero Suppression Trigger, iscompatible with the existing interfaces of the PC software, butis also capable to verify and filter incoming signals and transferonly recognized events. The results of the implementation andsimulation are presented

Soft X-ray diagnostic system upgrades and data quality monitoring features for tokamak usage

The validation of the measurements quality after on-site diagnostic system installation is necessary in order to provide reliable data and output results. This topic is often neglected or not discussed in detail regarding measurement systems. In the paper recently installed system for soft X-ray measurements is described in introduction. The system is based on multichannel GEM detector and the data is collected and sent in special format to PC unit for further postprocessing. The unique feature of the system is the ability to compute final data based on raw data only. The raw data is selected upon algorithms by FPGA units. The FPGAs are connected to the analog front-end of the system and able to register all of the signals and collect the useful data. The interface used for data streaming is PCIe Gen2 x4 for each FPGA, therefore high throughput of the system is ensured. The paper then discusses the properties of the installation environment of the system and basic functionality mode. New features are described, both in theoretical and practical approach. New modes correspond to the data quality monitoring features implemented for the system, that provide extra information to the postprocessing stage and final algorithms. In the article is described also additional mode to perform hardware simulation of signals in a tokamak-like environment using FPGAs. The summary describes the implemented features of the data quality monitoring features and additional modes of the system

Design of soft-X-ray tomographic system in WEST using GEM detectors

In metallic tokamaks, the interplay between particle transport and MagnetoHydroDynamic (MHD) activity might lead to impurities accumulation and finally to disruption. Studying such phenomena is thus essential if stationary discharges are to be achieved. Measuring the soft X-ray (SXR) radiation ([0.1 keV; 20 keV]) of magnetic fusion plasmas is a standard way of accessing valuable information on particle transport and MHD. Generally, like at Tore Supra (TS), the analysis is performed with a 2D tomographic system composed of several cameras equipped with silicon barrier diodes (SBD). On WEST the installation of an upper divertor masks many of the actual TS vertical diodes so that no proper tomography is possible. This paper presents the design of a new SXR diagnostic for the WEST project developed in collaboration with IPPLM (Poland) and the Warsaw University of Technology, based on a triple gas electron multiplier (GEM) detector. Preliminary simulations performed to size and position the detector and its electronics inside the vertical thimble are also presented, in particular estimation of magnetic field and temperature variation affecting GEM spatial resolution and signal quality. As a conclusion, perspectives about tomographic capabilities of the new system for studying impurity transport are given

Synchronization methods for the PAC RPC trigger system in the CMS experiment

The PAC (pattern comparator) is a dedicated muon trigger for the CMS (Compact Muon Solenoid) experiment at the LHC (Large Hadron Collider). The PAC trigger processes signals provided by RPC (resistive plate chambers), a part of the CMS muon system. The goal of the PAC RPC trigger is to identify muons, measure their transverse momenta and select the best muon candidates for each proton bunch collision occurring every 25 ns. To perform this task it is necessary to deliver the information concerning each bunch crossing from many RPC chambers to the trigger logic at the same moment. Since the CMS detector is large (the muon hits are spread over 40 ns), and the data are transmitted through thousands of channels, special techniques are needed to assure proper synchronization of the data. In this paper methods developed for the RPC signal synchronization and synchronous transmission are presented. The methods were tested during the MTCC (magnet test and cosmic challenge). The performance of the synchronization methods is illustrated by the results of the tests

Performance of the CMS muon trigger system in proton-proton collisions at √s = 13 TeV

The muon trigger system of the CMS experiment uses a combination of hardware and software to identify events containing a muon. During Run 2 (covering 2015-2018) the LHC achieved instantaneous luminosities as high as 2 × 10 cm s while delivering proton-proton collisions at √s = 13 TeV. The challenge for the trigger system of the CMS experiment is to reduce the registered event rate from about 40 MHz to about 1 kHz. Significant improvements important for the success of the CMS physics program have been made to the muon trigger system via improved muon reconstruction and identification algorithms since the end of Run 1 and throughout the Run 2 data-taking period. The new algorithms maintain the acceptance of the muon triggers at the same or even lower rate throughout the data-taking period despite the increasing number of additional proton-proton interactions in each LHC bunch crossing. In this paper, the algorithms used in 2015 and 2016 and their improvements throughout 2017 and 2018 are described. Measurements of the CMS muon trigger performance for this data-taking period are presented, including efficiencies, transverse momentum resolution, trigger rates, and the purity of the selected muon sample. This paper focuses on the single- and double-muon triggers with the lowest sustainable transverse momentum thresholds used by CMS. The efficiency is measured in a transverse momentum range from 8 to several hundred GeV