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Hadamard transformation based frequency response mismatch calibration for a 4-channel TIADC

JOURNAL OF INSTRUMENTATION 2024年第6期19卷 P06006页

作者： Qian, Lei Zheng, Yanze Mei, Sitao Sun, Sicheng Xu, Huiya Guo, Lianping Zhao, Yijiu Univ Elect Sci & Technol China Sch Automat Engn Chengdu 611731 Peoples R China UESTC Shenzhen Inst Adv Study Shenzhen 518110 Peoples R China

The time -interleaved analog -to -digital converter (TIADC) is one of the most effective solutions for improving the sampling rate of acquisition systems. However, the frequency response mismatch between channels can seriously degrade the performance of the system. In this paper, we propose a calibration method for frequency response mismatches in 4 -channel TIADC systems. Following the construction of a four -channel TIADC model using a four -order Hadamard matrix, the error signals were extracted using three time -invariant filters and subsequently subtracted from the output to complete the calibration. It uses the Hadamard transform instead of the complex exponential modulator used in conventional time -varying filter methods, which can further simplify the signal processing without the necessity of complicated calculations. We have employed a stimulated fourchannel TIADC system to validate the effectiveness of the proposed calibration technique. Moreover, in a commercial 12.5 GSPS four -channel TIADC system, it is also demonstrated that this approach is effective in improving the spurious -free dynamic range of the system.

关键词： Digital signal processing (DSP) data acquisition concepts data processing methods

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Doppler backscattering systems on the Globus-M2 tokamak

Doppler backscattering systems on the Globus-M2 tokamak

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4th European Conference on Plasma Diagnostics (ECPD)

作者： Yashin, A. Y. Bulanin, V. V. Gusev, V. K. Minaev, V. B. Petrov, A., V Petrov, Y., V Ponomarenko, A. M. Varfolomeev, V., I Peter Great St Petersburg Polytech Univ St Petersburg Russia Ioffe Inst St Petersburg Russia

Doppler backscattering (DBS) was successfully previously used on the Globus-M tokamak. The diagnostic was utilised in the form of either a single-frequency or a four-frequency dual homodyne system. It was used primarily for the study of zonal flows, filaments and Alfve acute accent n eigenmodes. These phenomena are worth being studied both on the periphery and in the core region of the plasma in a tokamak. For this specific reason two multifrequency DBS systems were installed on the upgraded Globus-M2 tokamak. The first four-frequency system with dual homodyne detection had already been used on the Globus-M tokamak and has lower probing frequencies which provide measurements from the periphery plasma. The second and new six frequency DBS system was installed with a non-linear transmission line that was adapted to generate probing signals at frequencies 50, 55, 60, 65, 70 and 75 GHz. In general, the range of probing frequencies corresponds to the region of critical plasma densities from 5 x 10(18) to 7 x 10(19) m(-3) at normal incidence. The pyramidal horn antennas are located inside the vacuum vessel with a special cardan-like rotator outside the camera so as to tilt antennas in the toroidal and poloidal directions. A previously developed code was applied to simulate 3D raytracing for all frequency channels. Calculations were carried out for different angles of incidence and for different electron density distributions in order to investigate the possibilities of the implementation of radial and poloidal correlation Doppler reflectometry. Examples of the DBS system application for study of plasma properties in the Globus-M2 tokamak are presented.

关键词： Nuclear instruments and methods for hot plasma diagnostics data processing methods

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Application of 2 x 5 MPX3 camera with monolithic sensor for phase contrast imaging and computed tomography

Application of 2 x 5 MPX3 camera with monolithic sensor for ...

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22nd International Workshop on Radiation Imaging Detectors

作者： Vavrik, D. Dudak, J. Kumpova, I Zemlicka, J. Czech Acad Sci Inst Theoret & Appl Mech Prosecka 76 Prague 6 Czech Republic Czech Tech Univ Inst Expt & Appl Phys Husova 240-5 Prague 1 Czech Republic

This work focuses on the non-destructive identification of delamination in layered structures utilizing the X-ray phase contrast effect. This effect naturally occurs on sharp edges, material interfaces and fine textures, and can be retrieved from radiographic data even without any grating in special cases, as will be demonstrated for the layered carbon fibre reinforced plastic composites used in the aerospace industry. Such delamination can be described as the local disbonding of composite layers, which often occurs due to the cyclic loading of the structural elements while in service. Such a flaw may significantly decrease its bearing capacity, and therefore periodic non-destructive inspection is needed. Aside from ultrasound inspection, which provides limited resolution and detectability, X-ray imaging and tomography is widely used in practise. Nevertheless, the identification of delamination may be difficult utilizing X-ray computed tomography, as delaminated faces may remain in contact - the defect has negligible volume. On the other hand, the distance between faces is not relevant for X-ray phase contrast imaging. In addition, access to the structural elements is often limited for X-ray imaging. For shaped parts, it will be shown in this work that limited access is not as critical a problem in comparison with standard computed tomography.

关键词： data processing methods Detection of defects Image filtering Inspection with X-rays

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Versatile free-running ADC-based data acquisition system for particle detectors

Versatile free-running ADC-based data acquisition system for...

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作者： Jokhovets, L. Kulessa, P. Erven, A. Grewing, C. von der Gracht, T. Hahnraths Harff, M. Ohm, H. Pysz, K. Ritman, J. Roth, C. Schloesser, M. Sefzick, T. Serdyuk, V Waasen, S. v. Wintz, P. Forschungszentrum Julich D-52428 Julich Germany GSI Darmstadt D-64291 Darmstadt Germany Ruhr Univ Bochum D-44801 Bochum Germany Inst Nucl Phys PAN PL-31342 Krakow Poland

A high-density and low-power (<300 mW/channel) data acquisition (DAQ) system integrating 2240 readout channels inside a single OpenVPX crate is presented. It is intended to be used in various applications, e.g. gaseous or scintillator-based particle detectors. 14 payload slots, controller and data concentrator communicate via a multi-gigabit backplane. Each payload slot consists of a front module for digital and a rear transition module for analog processing. A pair of modules implements 160 full readout chains including amplification/shaping, sampling, and feature extraction. The sampling rate and ADC resolution are configurable for 100-1000 MS/s and 14-8 bit, respectively. To extract the pulse arrival time we used a proper shaping of signals and a timing algorithm based on a non-linear rise approximation, which strongly reduces the sampling phase error, thus providing a good performance at moderate (100-250 MS/s) sampling rates. This allows raw data acquisition, arrival time extraction, energy calculation, and pile-up reconstruction for all 160 channels to be implemented in a single FPGA. It occupies less than 30% of its processing resources. The system was tested using the proton beam at COSY (Cooler Synchrotron) at Juelich Research Center (Germany). An off-detector DAQ with a 12-m long cabling was investigated. It introduces considerable additional thermal noise and crosstalk affecting the timing performance. For a sampling rate of 150 MS/s, the time resolution was found to be about 270 ps.

关键词： data acquisition circuits data processing methods Front-end electronics for detector readout Analogue electronic circuits

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Performance of JT-60SA Thomson Scattering data analysis system

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JOURNAL OF INSTRUMENTATION 2024年第4期19卷 C04011-C04011页

作者： Akimitsu, M. Ohtani, Y. Funaba, H. Tojo, H. D'Isa, F. A. Sasao, H. Nakano, T. Yoshida, M. Natl Inst Quantum Sci & Technol QST Naka Fusion Inst 801-1 Mukoyama Naka 3110193 Japan Natl Inst Nat Sci Natl Inst Fusion Sci 322-6 Oroshi Cho Toki Gifu 5095292 Japan Univ Padua Consorzio RFX CNR ENEAINFNAcciaierie Venete SpA Corso Stati Uniti 4 I-35127 Padua Italy

We have developed signal processing routines for the Thomson Scattering measurement, which is planned for use in the next campaign of the JT-60SA large-scale tokamak experiment. This paper provides the data analysis system and its performance evaluated in terms of computation time and error. The sequential routine of determining the scattered light intensity from a simulated signal, including noise data from a 1 Gs/s high-speed sampling digitizer, and determining the electron temperature and density was tested for the first time on an actual machine. The data analysis system ensures that electron temperature and density can be calculated with reasonable relative errors and within a realistic time frame for operations on JT-60SA.

关键词： data processing methods Plasma diagnostics- interferometry spectroscopy and imaging

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Three data-selection approaches for beam position monitor offline calibration

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JOURNAL OF INSTRUMENTATION 2024年第6期19卷 T06006页

作者： Kim, Geunwoo Kim, Eun-San Kwon, Jang Won Jang, Siwon Korea Univ Dept Accelerator Sci Sejong 30019 South Korea Inst Basic Sci IBS Inst Rare Isotope Sci Daejeon 34000 South Korea POSTECH Pohang Accelerator Lab Pohang 37673 South Korea

In this study, we describe the fabrication of an electrostatic beam position monitor (BPM) for beam diagnostic systems. Calibration of the BPM pickup requires both sensitivity and curve fitting owing to manufacturing tolerances following fabrication. To calibrate the BPM, we developed a BPM calibration system that comprises a wire -based test bench and readout electronics. We considered three difference -over -sum (DOS) data selection methods: DOS diag , DOS axis , and DOS all , to understand their impact on calibration accuracy. Each method selected specific DOS data, and we compared their characteristic curves. Consequently, we analyzed the calibration results by performing linear, 3rd -order, 5th -order, and two-dimensional (2D) 3rd -order polynomial fitting. Each of the three DOS data selection methods was examined to illustrate their advantages and limitations in terms of calibration accuracy and required amount of data. The results obtained demonstrated that choosing the appropriate DOS data -selection approach could be employed for the BPM offline calibrations, achieving minimized calibration errors and optimized response characteristics with polynomial curve fitting.

关键词： Beam-line instrumentation (beam position and profile monitors beam-intensity monitors bunch length monitors) data processing methods data reduction methods

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data processing Engine (DPE): data analysis tool for particle tracking and mixed radiation field characterization with pixel detectors Timepix

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JOURNAL OF INSTRUMENTATION 2024年第4期19卷 C04026页

作者： Marek, L. Granja, C. Jakubek, J. Ingerle, J. Turecek, D. Vuolo, M. Oancea, C. ADVACAM Pergamenky 12 Prague Czech Republic Charles Univ Prague Fac Math & Phys V Holesovickach 2 Prague Czech Republic European Space Agcy ESTEC NL-2200 AG Noordwijk Netherlands

Hybrid semiconductor pixelated detectors from the Timepix family are advanced detectors for online particle tracking, offering energy measurement and precise time stamping capabilities for particles of various types and energies. This inherent capability makes them highly suitable for various applications, including imaging, medical fields such as radiotherapy and particle therapy, space-based applications aboard satellites and the International Space Station, and industrial applications. The data generated by these detectors is complex, necessitating the development and deployment of various analytical techniques to extract essential information. For this purpose, and to aid the Timepix user community, it was designed and developed the "data processing Engine" (DPE) as an advanced tool for data processing designed explicitly for Timepix detectors. The functionality of the DPE is structured into three distinct processing levels: i) Pre-processing: this phase involves clusterization and the application of necessary calibrations and corrections. ii) processing: this stage includes particle classification, employing machine learning algorithms, and the recognition of radiation fields. iii) Post-processing: involves various analyses, such as directional analysis, coincidence analysis, frame analysis, Compton directional analysis, and the generation of physics products, are performed. The core of the DPE is supported by an extensive experimental database containing calibrations and referential radiation fields of typical environments, including protons, ions, electrons, gamma rays and X rays, as well as thermal and fast neutrons. To enhance accessibility, the DPE is implemented into various user interface platforms such as a command-line tool, an application programming interface, and as a graphical user interface in the form of a web portal. The DPE's broad utility is exemplified through its integration into various applications and developments.

关键词： data processing methods Particle identification methods Particle tracking detectors (Solid-state detectors)

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Signal classification algorithms for the MRPC with DRS4 readout

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JOURNAL OF INSTRUMENTATION 2024年第4期19卷 P04002页

作者： Malakhov, A. Daribayeva, A. Dmitriev, A. Joint Inst Nucl Res Joliot Curie 6 Dubna Russia

The readout electronics of the Multigap Resistive Plate Chambers (MRPC) of the NA61/SHINE experiment at CERN are based on the Domino Ring Sampler v.4 (DRS4) chips. Due to the analyzing complexity of the waveforms produced by the MRPC with DRS4 readout, one needs to develop a reliable algorithm in order to distinguish signal from noise. Two methods are investigated, using the beam test data on MRPC with DRS4 readout held at "PAKHRA" accelerator in LPI RAS, Troitsk. Their results are estimated within the comparative approach, as well as the possibility of their implementation for different purposes.

关键词： data processing methods data reduction methods

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Local feature expansion Vision Transformer model for bearing fault diagnosis under noise environments

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JOURNAL OF INSTRUMENTATION 2024年第3期19卷 P03018页

作者： Zhang, Xinliang Xie, Hongbin Zhou, Yitian Jia, Lijie Henan Polytech Univ Sch Elect Engn & Automat Henan Int Joint Lab Direct Drive & Control Intell Jiaozuo 454003 Peoples R China Zhoushan Yangwangnaxin Technol Co Ltd Zhoushan 3161041 Zhejiang Peoples R China

Vision Transformer (ViT) shows potential in bearing fault diagnosis due to its multi -head self -attention mechanism and parallel feature extraction network which are efficient to achieve the robust complete feature representation of the fault. However, its adaption to the noise interference relies on the sufficient huge amount of training samples to prepare the local features of the fault and may suffer performance degradation when only a limited number of samples are available for the model training. To combat this challenge, an improved ViT diagnosis model based on the local feature expansion, i.e., LFE-ViT, is proposed. An auxiliary feature extraction block is introduced using a local feature expansion network and works as a parallel module with the ViT encoder. Through the enlargement of the receptive field, the multi -scale local features on a high dimensional space are available upon the limited samples. Then, through a feature embedding channel, the extracted local features are transmitted to the ViT encoder. Finally, by virtue of the multi -head self -attention mechanism to capture the time sequence global information, a fault diagnosis model comprising comprehensively local and global feature information is derived. Experimental validation on the bearing fault dataset from Case Western Reserve University shows that LFE-ViT has provided a rather satisfactory diagnosis performance under limited samples and noise environment.

关键词： Detection of defects Digital signal processing (DSP) data processing methods Overall mechanics design (support structures and materials vibration analysis etc)

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Pragmatic method for fast programming of hybrid photon counting detectors

Pragmatic method for fast programming of hybrid photon count...

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22nd International Workshop on Radiation Imaging Detectors

作者： Bacchi, C. Dawiec, A. Orsini, F. Synchrotron SOLEIL St Aubin BP 48 F-91192 Gif Sur Yvette France

It is now been over 15 years since Hybrid Photon Counting Detectors (HPCD) became one of the standard position-sensitive detectors for synchrotron light sources and X-ray detection applications. This is mainly due to their single-photon sensitivity over a high dynamic energy range and electronic noise suppression thanks to energy thresholding. To reach those performances, all HPCD pixels must feature the same electrical response against photons of the same energy. From the analysis of a monochromatic beam, in case of an ideal HPCD detector, it would be sufficient to apply a fixed voltage threshold among all pixels, positioned at half of the mean pulse amplitude to count every photon above the threshold. However, in practical cases, it must be considered that noise baselines from all pixels are not always strictly located at the same voltage level but can be spread over some voltage ranges. To address this kind of issue, most of all HPCDs apply a conventional threshold equalization method, that mainly relies on three steps;the setting of a global threshold at an arbitrary value, the identification of pixels noise baseline around that global threshold through an in-pixel threshold trimmer, and the computation of the required threshold offsets for setting all pixels at their own noise baseline at the same time. However, in case of a firsttime use of an HPCD prototype, the threshold equalization might be biased by parameters that are wrongly set. Those biases can sometimes be characterized by the inability to localize some pixel noise baselines, which could be outside the voltage range of the threshold trimmer. The recovery of those biased pixels could be performed by changing the position of the global threshold, or by increasing the voltage range of the threshold trimmer. Unfortunately, both solutions could be time consuming due to the lack of information on the required steps for recovering all noise baselines. In order to overcome this issue in a reasonable time, th

关键词： Analysis and statistical methods data processing methods data acquisition concepts X-ray detectors

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