Speaker
Tomasz Czarski
(Institute of Plasma Physics and Laser Microfusion)
Description
The measurement system based on GEM - Gas Electron Multiplier detector is developed for X‑ray diagnostics of magnetic confinement tokamak plasmas. The multi-channel setup is designed for estimation of the energy and the position distribution of an X-ray source. The main 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 samples of the ADC – Analog-to-Digital Converter which are triggered by the detector current are acquired independently for the measurement channels. The FPGA – Field-Programmable Gate Array based system performs the basic functions of data processing: data receiving, signals selection, charge estimation and memory operation. High flux radiation cause the problem of coinciding signals for cluster charge identification. The amplifier with shaper determines time characteristics and limits the pulses frequency. The essential assumption is that ADC overlapping signals can be reconstructed if primary GEM pulses do not coincide. The ending tail of the signal can be restored for the given electronics characteristics. The proposed algorithm can be apply iteratively for series of superimposed pulses. Separation of coincided signals was introduced and verified for simulation experiments. On line separation of overlapped signals was implemented applying the FPGA technology with relatively simple firmware procedure. Representative results for reconstruction of coinciding signals are demonstrated. Radiation source properties are presented by the histograms for selected range of position, time intervals and cluster charge values corresponding to the energy spectra.
Co-authors
Andrzej Wojenski
(Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland)
Grzegorz Kasprowicz
(Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland)
Karol Malinowski
(Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland)
Krzysztof Pozniak
(Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland)
Maryna Chernyshova
(Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland)
Piotr Kolasinski
(Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland)
Rafal Krawczyk
(Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland)
Tomasz Czarski
(Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland)
Wojciech Zabolotny
(Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland)
