Wojenski A, Linczuk P, Kasprowicz G, Poźniak K T, Chernyshova M, Mazon D, Czarski T, Krawczyk R D, Malard P, Malinowski K, Kolasinski P, Gąska M
Warsaw University of Technology, Institute of Electronic Systems, Nowowiejska 15/19, 00-665 Warsaw, Poland.
Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland.
Rev Sci Instrum. 2021 May 1;92(5):054704. doi: 10.1063/5.0042546.
The work describes a novel approach to the design of a fast, multichannel measurement system for plasma diagnostics [A. Wojenski et al., Fusion Eng. Des. 123, 727 (2016)]. Its main scope is to provide measurements of soft X-ray (SXR) emission during plasma phenomena at the W-Environment in Steady-state Tokamak (WEST), especially for monitoring and tracing tungsten impurities. This paper describes the vertical Gas Electron Multiplier (GEM) camera installed at the WEST [M. Chernyshova et al., J. Instrument. 10, P10022 (2015)]. The designed GEM detector readout board has more than 100 channels, resulting in high-performance requirements for the data acquisition and processing system. The novel system construction approach is that the unit works on the raw signals providing a high quality of the data, especially in the scope of pileup effect analysis. In the case of doubtful results, the source data can be easily reviewed offline. The data selection and transmission are done in Field-Programmable Gate Arrays (FPGAs) on the custom boards with the custom Peripheral Component Interconnect (PCI)-Express Gen2 switch that allows us to register signals from multiple FPGAs and then process the data by complex algorithms [G. Kasprowicz et al., J. Fusion Energy 38, 480 (2019)]. The firmware is replaceable and different working modes can be applied (some under verification): global trigger mode, high-speed data serialization, and extended signal registration. Low level optimized central processing unit software for data readout was also designed [P. Linczuk et al., J. Instrum. 14, C05001 (2019)]. The installation of the system is described due to complex system components' distribution. The first results of the successful acquisition of the plasma at the WEST are discussed. The corresponding SXR energy and topology spectra were computed. Those are the first technical measurements of the system to ensure verification of data quality.
这项工作描述了一种用于等离子体诊断的快速多通道测量系统设计的新方法[A. Wojenski等人，《聚变工程与设计》123, 727 (2016)]。其主要目的是在稳态托卡马克（WEST）的钨环境下的等离子体现象期间提供软X射线（SXR）发射的测量，特别是用于监测和追踪钨杂质。本文描述了安装在WEST的垂直气体电子倍增器（GEM）相机[M. Chernyshova等人，《仪器仪表杂志》10, P10022 (2015)]。所设计的GEM探测器读出板有100多个通道，这对数据采集和处理系统提出了高性能要求。新颖的系统构建方法是该单元对原始信号进行处理，提供高质量的数据，特别是在堆积效应分析方面。在结果存疑的情况下，可以很容易地离线查看源数据。数据选择和传输在定制板上的现场可编程门阵列（FPGA）中完成，该定制板带有定制的外围组件互连（PCI）-Express Gen2交换机，使我们能够记录来自多个FPGA的信号，然后通过复杂算法处理数据[G. Kasprowicz等人，《聚变能源杂志》38, 480 (2019)]。固件是可替换的，可以应用不同的工作模式（有些正在验证中）：全局触发模式、高速数据序列化和扩展信号记录。还设计了用于数据读出的低级别优化中央处理器软件[P. Linczuk等人，《仪器仪表杂志》14, C05001 (2019)]。由于系统组件分布复杂，描述了系统的安装情况。讨论了在WEST成功采集等离子体的初步结果。计算了相应的SXR能量和拓扑光谱。这些是系统的首次技术测量，以确保数据质量的验证。
