FPGA-based novel real-time evaluation and data quality monitoring system for tokamak high-performance GEM soft X-ray diagnostic

Abstract

Based on literature review data quality monitoring topic is often being simplified in case of tokamak diagnostic systems. In previous publications Authors presented a novel model of real-time evaluation and data quality monitoring (EDQM) sub-system for use in physics experiments, mostly related to tokamak plasma measurements. The implementation of model is done in scope of monitoring raw output signals from Gas Electron Multiplier detectors used in FPGA-based soft X-ray diagnostics. System is designed to work in the real-time feedback loop for parameters control of tokamak in scope of achieving long-term plasma stability. In the paper are described results of application the DQM engine from measurements with 112-channel GEM detector and real radiation sources (isotopes, X-ray tube). The discussion provided in article covers the usefulness of applied novel EDQM techniques: technical and statistical, in scope of detection of new, corrupted output signals from the GEM detector when working under hard environment conditions. The presented in the paper results indicates the ability of the detection of subtle system defects (e.g. detector, electronics), resulting in the significant corruption of the output products of measured radiation: energy and topological spectra. This is especially important for the systems working in the real-time feedback loop. The novel approach of detection new malformed signals with ability to automatically discard those phenomena from further analysis is also described. In the summary there are described benefits of usage of the proposed novel DQM approach with indication of another unique work for further CPU extensions of the EDQM sub-system providing complex FPGA-CPU high-performance data quality monitoring unit. The EDQM system is planned to be installed in GEM SXR diagnostics on WEST tokamak.