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Natrium: Use of FPGA embedded processors for real-time data compression

JOURNAL OF INSTRUMENTATION 2011年第12期6卷 C12036-C12036页

作者： Ammendola, R. Biagioni, A. Frezza, O. Lo Cicero, F. Lonardo, A. Rossetti, D. Salamon, A. Salina, G. Simula, F. Tosoratto, L. Vicini, P. INFN Sez Roma Tor Vergata Rome Italy INFN Sez Roma Rome Italy

We present test results and characterization of a data compression system for the readout of the NA62 liquid krypton calorimeter trigger processor. The Level-0 electromagnetic calorimeter trigger processor of the NA62 experiment at CERN receives digitized data from the calorimeter main readout board. These data are stored on an on-board DDR2 RAM memory and read out upon reception of a Level-0 accept signal. The maximum raw data throughput from the trigger front-end cards is 2.6 Gbps. To readout these data over two Gbit Ethernet interfaces we investigated different implementations of a data compression system based on the Rice-Golomb coding: one is implemented in the FPGA as a custom block and one is implemented on the FPGA embedded processor running a C code. The two implementations are tested on a set of sample events and compared with respect to achievable readout bandwidth.

关键词： data processing methods Computing (architecture, farms, GRID for recording, storage, archiving, and distribution of data) data reduction methods Digital electronic circuits

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Investigation of thickness uniformity of thin metal films by using α-particle energy loss method and successive scanning measurements

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JOURNAL OF INSTRUMENTATION 2017年第3期12卷 T03001-T03001页

作者： Li, Gang Xu, Jiayun Bai, Lixin Sichuan Univ Dept Nucl Engn & Technol Coll Phys Sci & Technol Chengdu 610064 Sichuan Peoples R China

The metal films are widely used in the Inertial Confinement Fusion (ICF) experiments to obtain the radiation opacity, and the accuracy of the measuring results mainly depends on the accuracy of the film thickness and thickness uniformity. The traditional used measuring methods all have various disadvantages, the optical method and stylus method cannot provide mass thickness which reflects the internal density distribution of the films, and the weighing method cannot provide the uniformity of the thickness distribution. This paper describes a new method which combines the alpha-particle energy loss (AEL) method and the successive scanning measurements to obtain the film thickness and thickness uniformity. The measuring system was partly installed in the vacuum chamber, and the relationship of chamber pressure and energy loss caused by the residual air in the vacuum chamber was studied for the source-to-detector distance ranging from 1 to 5 cm. The results show that the chamber pressure should be less than 10 Pa for the present measuring system. In the process of measurement, the energy spectrum of alpha-particles transmitted through each different measuring point were obtained, and then recorded automatically by a self-developed multi-channel analysis software. At the same time, the central channel numbers of the spectrum (CH) were also saved in a text form document. In order to realize the automation of data processing and represent the thickness uniformity visually in a graphic 3D plot, a software package was developed to convert the CH values into film thickness and thickness uniformity. The results obtained in this paper make the film thickness uniformity measurements more accurate and efficient in the ICF experiments.

关键词： Analysis and statistical methods data processing methods Spectrometers

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A digital system of acquisition and coincidence for SANS

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JOURNAL OF INSTRUMENTATION 2020年第11期15卷

作者： Hu, S. Zhang, X. Shen, F. Zhou, R. Zuo, J. Sichuan Univ Coll Phys Chengdu 610065 Peoples R China

We have developed multi-channel signal acquisition with a coincidence digital circuit for a two-dimensional detector array of the small-angle neutron scattering spectrometer (SANS) of the Institute of Nuclear Physical Chemistry at the Chinese Academy of Engineering Physics. This paper discusses how to determine such factors as the coincidence time window and program dead time according to the characteristics of the detector signal and how to correct the timer to realize the data coincidence. The whole system can support up to 192 analog channels connected to a fast analog-to-digital converter, supporting speeds of 50 MSPS for each channel managed by a field-programmable gate array (FPGA). The internal clock of the FPGA is 50 MHz and the time accuracy is 20 ns. Preliminary experiments are carried out and the results are presented and discussed. The whole design can fully meet the needs of the spectrometer.

关键词： Analysis and statistical methods data acquisition concepts data processing methods Neutron diffraction detectors

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Transport of covariance matrices in the inhomogeneous magnetic field of the ATLAS experiment by the application of a semi-analytical method

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JOURNAL OF INSTRUMENTATION 2009年第4期4卷 P04016-P04016页

作者： Lund, E. Bugge, L. Gavrilenko, I. Strandlie, A. Univ Oslo N-0316 Oslo Norway CERN European Org Nucl Res CH-1211 Geneva 23 Switzerland PN Lebedev Phys Inst Moscow 117924 Russia Gjovik Univ Coll N-2802 Gjovik Norway

In this paper we study the transport of track parameter covariance matrices - the so-called error propagation - in the inhomogeneous magnetic field of the ATLAS experiment. The Jacobian elements are transported in parallel with the track parameters, avoiding the inherent need of any purely numerical scheme of propagating a set of auxiliary tracks. We evaluate the quality of the transported Jacobians by a very thorough, purely numerical approach of obtaining the same derivatives, providing a quantitative understanding of the effects of including gradients of energy loss and the magnetic field on the accuracy of the error propagation. Irrespective of the accuracy of the underlying track parameter propagation, the method of parallel integration of the derivatives is demonstrated to be significantly faster than even the simplest numerical scheme. The error propagation presented in this paper is part of the simultaneous track and error propagation ( STEP) algorithm of the common ATLAS tracking software.

关键词： Pattern recognition, cluster finding, calibration and fitting methods Simulation methods and programs data processing methods

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dataCloud infrastructure to manage FAIR environmental data

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JOURNAL OF INSTRUMENTATION 2020年第4期15卷

作者： Aguilar, F. IFCA CSIC Ave Castros S-N Ed Juan Jorda Santander Cantabria Spain

The use of Jupyter notebooks as a platform for data management is becoming popular in different disciplines thanks to the features provided: web-based interface, code running capabilities, customization, kernel configuration, etc. However, it is sometimes limited to the server capacity, so working with big datasets is difficult since certain data analysis requires intensive computing or even GPUs. Thanks to diverse Cloud Computing-based solutions, especially those provided by eXtreme-dataCloud project, these limitations can be solved, providing an integrated environment where storage and computing resources could support a system in a transparent way for the user.

关键词： Computing (architecture, farms, GRID for recording, storage, archiving and distribution of data) Software architectures (event data models, frameworks and databases) data processing methods

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Refining scan positions in Ptychography through error minimisation and potential application of Machine Learning

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JOURNAL OF INSTRUMENTATION 2018年第6期13卷 C06002-C06002页

作者： Guzzi, F. Kourousias, G. Bille, F. Pugliese, R. Reis, C. Gianoncelli, A. Carrato, S. Univ Trieste Dept Engn & Architecture DIA Via A Valerio 10 I-34127 Trieste Italy Elettra Sincrotrone Trieste SCpA Str Statale 14AREA Sci Pk I-34149 Trieste Italy

Ptychography is an advanced technique whose latest developments have allowed for exceptionally high resolution in X-ray microscopy, as well as new setups that can even be lensless;the spatial resolution has already reached <5 nm in synchrotron beamlines. Still there are certain demanding requirements such as beam coherence and strong involvement of computational methods that make it a rather difficult technique to implement. In this paper we introduce a computational work-flow aiming at refining the individual probe positions of a ptychography scan. Indeed, the precision of those positions is of high importance as it impacts the reconstruction. Special setups using precise sample stages with nanopositioning and advanced interferometers are important;however, positioning errors still remain a problem for many operating laboratories. This paper examines the Structural Similarity Index as a suitable metric for evaluating the registration in alignment of individually reconstructed probes. Eventually it suggests the use of Machine Learning techniques as future direction in probe alignment. It also presents a new software tool for precise manual alignment and visualization. All the software developed during this research project is provided to the scientific community as open source.

关键词： data processing methods Analysis and statistical methods

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Kernel density estimation of a multidimensional efficiency profile

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JOURNAL OF INSTRUMENTATION 2015年第2期10卷 P02011-P02011页

作者： Poluektov, A. Univ Warwick Coventry CV4 7AL W Midlands England Budker Inst Nucl Phys Novosibirsk 630090 Russia

Kernel density estimation is a convenient way to estimate the probability density of a distribution given the sample of data points. However, it has certain drawbacks: proper description of the density using narrow kernels needs large data samples, whereas if the kernel width is large, boundaries and narrow structures tend to be smeared. Here, an approach to correct for such effects, is proposed that uses an approximate density to describe narrow structures and boundaries. The approach is shown to be well suited for the description of the efficiency shape over a multidimensional phase space in a typical particle physics analysis. An example is given for the five-dimensional phase space of the Lambda(0)(b) -> D(0)p pi(-) decay.

关键词： Analysis and statistical methods data processing methods

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Correcting Intensity Drift in X-ray Grating-based Phase Contrast Imaging

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JOURNAL OF INSTRUMENTATION 2016年第3期11卷 C03055-C03055页

作者： Zhang, P. Shao, Q. Hu, R. Wang, S. Zan, G. Wang, S. Bao, Y. Wali, F. Tian, Y. Liu, G. Wang, Z. Gao, K. Univ Sci & Technol China Natl Synchrotron Radiat Lab Hefei 230027 Peoples R China Chinese Acad Sci Shanghai Inst Opt & Fine Mech Shanghai 201800 Peoples R China

X-ray phase-contrast imaging has become an attractive technique because it can deliver additional information on weakly absorbing materials. Grating-based phase contrast imaging with conventional x-ray source is a breakthrough in x-ray phase contrast imaging because it provides attenuation, refraction and scattering information simultaneously. Therefore, it has potential to be applied in medical and industrial applications. However, in actual experiments, we found that the photon intensity drift of the x-ray source would influence the final images, especially the refraction images. After analyzing the phase-stepping curve, we proposed a correction method to fix the problem due to the effect of intensity drift. The proposed correction method is successfully applied to grating-based phase-contrast imaging setup having un-stable x-ray source. The experimental results show that our method could solve this problem.

关键词： Computerized Tomography (CT) and Computed Radiography (CR) data processing methods X-ray radiography and digital radiography (DR) Inspection with x-rays

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Development of a plastic scintillation detector for muon scattering imaging

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JOURNAL OF INSTRUMENTATION 2020年第11期15卷

作者： Hu, T. Q. Liang, Z. Li, X. Li, C. Tang, Z. B. Wu, Y. T. Univ Sci & Technol China State Key Lab Particle Detect & Elect Hefei 230026 Peoples R China Univ Sci & Technol China Dept Modern Phys Hefei 230026 Peoples R China

To develop a device of large-area cosmic ray imaging in complex measurement environments, we design a muon scattering imaging detector composed of triangular scintillators, with a new type of photodetector (SiPM) as readout. A 500 mm x 500 mm imaging detector composed of multiple scintillator bars is presented in this paper. GEANT4 simulation shows that its intrinsic position resolution can be improved by the incidence angle and air gap corrections. To optimize its imaging performance, the reconstruction and correction methods of hit position are discussed in detail and compared with the experimental results.

关键词： Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc) Particle tracking detectors Simulation methods and programs data processing methods

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A new fast scanning system for the measurement of large angle tracks in nuclear emulsions

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JOURNAL OF INSTRUMENTATION 2015年第11期10卷 P11006-P11006页

作者： Alexandrov, A. Buonaura, A. Consiglio, L. D'Ambrosio, N. De Lellis, G. Di Crescenzo, A. Di Marco, N. Galati, G. Lauria, A. Montesi, M. C. Pupilli, F. Shchedrina, T. Tioukova, V. Vladymyrov, M. Ist Nazl Fis Nucl Sez Napoli I-80125 Naples Italy Russian Acad Sci LPI RUS-119991 Moscow Russia Ist Nazl Fis Nucl LNGS I-67100 Laquila Italy Univ Naples Federico II I-80125 Naples Italy Ist Nazl Fis Nucl LNF I-00044 Frascati Italy

Nuclear emulsions have been widely used in particle physics to identify new particles through the observation of their decays thanks to their unique spatial resolution. Nevertheless, before the advent of automatic scanning systems, the emulsion analysis was very demanding in terms of well trained manpower. Due to this reason, they were gradually replaced by electronic detectors, until the '90s, when automatic microscopes started to be developed in Japan and in Europe. Automatic scanning was essential to conceive large scale emulsion-based neutrino experiments like CHORUS, DONUT and OPERA. Standard scanning systems have been initially designed to recognize tracks within a limited angular acceptance (theta less than or similar to 30 degrees) where theta is the track angle with respect to a line perpendicular to the emulsion plane. In this paper we describe the implementation of a novel fast automatic scanning system aimed at extending the track recognition to the full angular range and improving the present scanning speed. Indeed, nuclear emulsions do not have any intrinsic limit to detect particle direction. Such improvement opens new perspectives to use nuclear emulsions in several fields in addition to large scale neutrino experiments, like muon radiography, medical applications and dark matter directional detection.

关键词： data processing methods Pattern recognition cluster finding calibration and fitting methods data acquisition concepts Performance of High Energy Physics Detectors

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