检索结果-内蒙古大学图书馆

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

JOURNAL OF INSTRUMENTATION 2016年第3期11卷

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

来源：评论

学校读者我要写书评

暂无评论

Complex interferometry potential in case of sufficiently stable diagnostic system

引用

JOURNAL OF INSTRUMENTATION 2016年第6期11卷

作者： Kalal, M. Czech Tech Univ Fac Nucl Sci & Phys Engn Brehova 7 CR-11519 Prague 1 Czech Republic

Classical interferometry is one of the key methods among active optical diagnostics. Its more advanced version, which allows recording and subsequent reconstruction of up to three sets of data using just one data object-a complex interferogram-was developed in the past and became known as complex interferometry. Employing this diagnostics, not only the usual phase shift, but also the amplitude of the probing beam as well as the fringe contrast (leading directly to the phase shift time derivative) can be reconstructed simultaneously from such a complex interferogram. In this paper it will be demonstrated that even in the case of a not particularly good diagnostic beam quality these three quantities can be reconstructed with a high degree of accuracy provided both the diagnostic beam as well as the corresponding optical line feature a reasonable stability. Such stability requirement is important as in an ideal case four shots need to be gradually recorded (one by one): the signal complex interferogram, the reference interferogram as well as the intensity structures of the signal and reference part of the diagnostic beam. Two examples of complex interferograms obtained in experiments will be analyzed: the laser produced plasma (spark in the air) and the high pressure gas jet. A general ray-tracing based iterative algorithm will be outlined in order to increase a precision of the index of refraction spatial profile taking into account refraction effects (omitted in the Abel inversion) and employing the original reconstructed phase shift and amplitude.

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

来源：评论

学校读者我要写书评

暂无评论

Classification of JET Neutron and Gamma Emissivity Profiles

引用

JOURNAL OF INSTRUMENTATION 2016年第5期11卷

作者： Craciunescu, T. Murari, A. Kiptily, V. Vega, J. Abhangi, M. Abreu, P. Aftanas, M. Afzal, M. Aggarwal, K. M. Aho-Mantila, L. Ahonen, E. Aints, M. Airila, M. Albanese, R. Alegre, D. Alessi, E. Aleynikov, P. Alfier, A. Alkseev, A. Allan, P. Almaviva, S. Alonso, A. Alper, B. Alsworth, I. Alves, D. Ambrosino, G. Ambrosino, R. Amosov, V. Andersson, F. Andersson Sunden, E. Angelone, M. Anghel, A. Anghel, M. Angioni, C. Appel, L. Apruzzese, G. Arena, P. Ariola, M. Arnichand, H. Arnoux, G. Arshad, S. Ash, A. Asp, E. Asunta, O. Atanasiu, C. V. Austin, Y. Avotina, L. Axton, M. D. Ayres, C. Bachmann, C. Baciero, A. Baiao, D. Bailescu, V. Baiocchi, B. Baker, A. Baker, R. A. Balboa, I. Balden, M. Balshaw, N. Bament, R. Banks, J. W. Baranov, Y. F. Barlow, I. L. Barnard, M. A. Barnes, D. Barnsley, R. Baron Wiechec, A. Baruzzo, M. Basiuk, V. Bassan, M. Bastow, R. Batista, A. Batistoni, P. Bauer, R. Bauvir, B. Bazylev, B. Beal, J. Beaumont, P. S. Becoulet, A. Bednarczyk, P. Bekris, N. Beldishevski, M. Bell, K. Belli, F. Bellinger, M. Belo, J. K. Belo, P. Belonohy, E. Benterman, N. A. Bergsaker, H. Bernardo, J. Bernert, M. Berry, M. Bertalot, L. Beurskens, M. N. A. Bieg, B. Bielecki, J. Biewer, T. Bigi, M. Bilkova, P. Binda, F. Bizarro, J. P. S. Bjorkas, C. Blackman, K. Blackman, T. R. Blanchard, P. Blanco, E. Blatchford, P. Bobkov, V. Boboc, A. Bodnar, G. Bogar, O. Bolzonella, T. Boncagni, L. Bonham, R. Bonheure, G. Boom, J. Booth, J. Borba, D. Borodin, D. Botrugno, A. Boulbe, C. Boulting, P. Bovert, K. V. Bowden, M. Bower, C. Boyce, T. Boyer, H. J. Bradshaw, J. M. A. Braic, V. Breizman, B. Bremond, S. Brennan, P. D. Brett, A. Brezinsek, S. Bright, M. D. J. Brix, M. Broeckx, W. Brombin, M. Brown, B. C. Brown, D. P. D. Brown, M. Bruno, E. Bucalossi, J. Buch, J. Buckley, M. A. Bucko, K. Budny, R. Bufferand, H. Bulman, M. Bulmer, N. Bunting, P. Buratti, P. Burcea, G. Burckhart, A. Buscarino, A. Butcher, P. R. Butler, N. K. Bykov, I. Byrne, J. Byszuk, A. Cackett, A. Cahyna, P. Cain, G. Calabro, G. Callaghan, C. P. Campling, D. C. Cane EUROfus Consortium JET Culham Sci Ctr Abingdon OX14 3DB Oxon England Natl Inst Laser Plasma & Radiat Phys Str Atomistilor409 POB MG-36 Bucharest 077125 Romania Univ Padua Acciaierie Venete SpA Consorzio RFX CNRENEAINFN Corso Stati Uniti 4 I-35127 Padua Italy Culham Sci Ctr Fus Energy CCFE Abingdon OX14 3DB Oxon England CIEMAT Lab Nacl Fus Ave Complutense 40 E-28040 Madrid Spain Aalto Univ FIN-00076 Aalto Finland BCS Barcelona Spain Culham Sci Ctr CCFE Abingdon OX14 3DB Oxon England IRFM CEA F-13108 St Paul Les Durance France Ctr Brasileiro Pesquisas Fis BR-22290180 Rio De Janeiro Brazil Consorzio CREATE I-80125 Naples Italy Consorzio RFX I-35127 Padua Italy Daegu Univ Gyongsan 712174 Gyeongbuk South Korea Univ Carlos III Madrid Dept Fis Madrid 28911 Spain Univ Ghent Dept Appl Phys B-9000 Ghent Belgium Chalmers Univ Technol Dept Earth & Space Sci SE-41296 Gothenburg Sweden Univ Cagliari Dept Elect & Elect Engn I-09123 Cagliari Italy Comenius Univ Fac Math Phys & Informat Dept Expt Phys Bratislava 84248 Slovakia Univ Strathclyde Dept Phys & Appl Phys Glasgow G4 ONG Lanark Scotland Uppsala Univ Dept Phys & Astron SE-75120 Uppsala Sweden Lund Univ Dept Phys SE-22100 Lund Sweden KTH SCI Dept Phys SE-10691 Stockholm Sweden Univ Oxford Dept Phys Oxford OX1 2JD England Univ Warwick Dept Phys Coventry CV4 7AL W Midlands England Queens Univ Dept Pure & Appl Phys Belfast BT7 1NN Antrim North Ireland Univ Catania Dipartimento Ingn Elettr Elettr & Sistemi I-95125 Catania Italy Dublin City Univ Dublin Ireland CRPP EPFL CH-1015 Lausanne Switzerland CNRS UMR 7648 Ecole Polytech F-91128 Palaiseau France EUROfus Programme Management Unit D-85748 Garching Germany Culham Sci Ctr EUROfus Programme Management Unit Abingdon OX14 3DB Oxon England European Commiss B-1049 Brussels Belgium FOM Inst DIFFER NL-3430 BE Nieuwegein Netherlands Forsch Zentrum Julich GmbH Inst Energie & Klimaforsch Plasmaphys D-52425 Julich Germany Fus En

In thermonuclear plasmas, emission tomography uses integrated measurements along lines of sight (LOS) to determine the two-dimensional (2-D) spatial distribution of the volume emission intensity. Due to the availability of only a limited number views and to the coarse sampling of the LOS, the tomographic inversion is a limited data set problem. Several techniques have been developed for tomographic reconstruction of the 2-D gamma and neutron emissivity on JET. In specific experimental conditions the availability of LOSs is restricted to a single view. In this case an explicit reconstruction of the emissivity profile is no longer possible. However, machine learning classification methods can be used in order to derive the type of the distribution. In the present approach the classification is developed using the theory of belief functions which provide the support to fuse the results of independent clustering and supervised classification. The method allows to represent the uncertainty of the results provided by different independent techniques, to combine them and to manage possible conflicts.

关键词： data processing methods Nuclear instruments and methods for hot plasma diagnostics Pattern recognition cluster finding calibration and fitting methods

来源：评论

学校读者我要写书评

暂无评论

Amplitude estimation of a sine function based on confidence intervals and Bayes' theorem

引用

JOURNAL OF INSTRUMENTATION 2016年第5期11卷

作者： Eversmann, D. Pretz, J. Rosenthal, M. Rhein Westfal TH Aachen Phys Inst B 3 Otto Blumenthal Str D-52056 Aachen Germany Forschungszentrum Julich JARA FAME Forces & Matter Expt D-52056 Aachen Germany Rhein Westfal TH Aachen D-52056 Aachen Germany Forschungszentrum Julich Inst Kernphys Wilhelm Johnen Str D-52428 Julich Germany

This paper discusses the amplitude estimation using data originating from a sine-like function as probability density function. If a simple least squares fit is used, a significant bias is observed if the amplitude is small compared to its error. It is shown that a proper treatment using the Feldman-Cousins algorithm of likelihood ratios allows one to construct improved confidence intervals. Using Bayes' theorem a probability density function is derived for the amplitude. It is used in an application to show that it leads to better estimates compared to a simple least squares fit.

关键词： Analysis and statistical methods data analysis Polarisation data processing methods

来源：评论

学校读者我要写书评

暂无评论

A new generation scanning system for the high-speed analysis of nuclear emulsions

引用

JOURNAL OF INSTRUMENTATION 2016年第6期11卷

作者： Alexandrov, A. Buonaura, A. Consiglio, L. D'Ambrosio, N. De Lellis, G. Di Crescenzo, A. Galati, G. Lauria, A. Montesi, M. C. Tioukov, V. Vladymyrov, M. INFN Sez Napoli I-80125 Naples Italy Russian Acad Sci LPI Lebedev Phys Inst RUS-119991 Moscow Russia Ist Nazl Fis Nucl Lab Nazl Gran Sasso I-67100 Laquila Italy Univ Naples Federico II I-80125 Naples Italy LHEP Bern Bern Switzerland

The development of automatic scanning systems was a fundamental issue for large scale neutrino detectors exploiting nuclear emulsions as particle trackers. Such systems speed up significantly the event analysis in emulsion, allowing the feasibility of experiments with unprecedented statistics. In the early 1990s, R&D programs were carried out by Japanese and European laboratories leading to automatic scanning systems more and more efficient. The recent progress in the technology of digital signal processing and of image acquisition allows the fulfillment of new systems with higher performances. In this paper we report the description and the performance of a new generation scanning system able to operate at the record speed of 84 cm(2)/hour and based on the Large Angle Scanning System for OPERA (LASSO) software infrastructure developed by the Naples scanning group. Such improvement, reduces the scanning time by a factor 4 with respect to the available systems, allowing the readout of huge amount of nuclear emulsions in reasonable time. This opens new perspectives for the employment of such detectors in a wider variety of applications.

关键词： data acquisition concepts data processing methods Image processing Optics

来源：评论

学校读者我要写书评

暂无评论

LHCb GPU acceleration project

引用

JOURNAL OF INSTRUMENTATION 2016年第1期11卷

作者： Badalov, A. Campora, D. Neufeld, N. Vilasis-Cardona, X. La Salle Univ Ramon Llull GR SETAD Quatre Camins 30 Barcelona Spain CERN CH-1211 Geneva 23 Switzerland

The LHCb detector is due to be upgraded for processing high-luminosity collisions, which will increase data bandwidth to the event filter farm from 100 GB/s to 4 TB/s, encouraging us to look for new ways of accelerating Online reconstruction. The Coprocessor Manager is a new framework for integrating LHCb's existing computation pipelines with massively parallel algorithms running on GPUs and other accelerators. This paper describes the system and analyzes its performance.

关键词： Software architectures (event data models, frameworks and databases) data processing methods

来源：评论

学校读者我要写书评

暂无评论

A new approach to theoretical investigations of high harmonics generation by means of fs laser interaction with overdense plasma layers. Combining particle-in-cell simulations with machine learning.

引用

JOURNAL OF INSTRUMENTATION 2016年第12期11卷

作者： Mihailescu, A. Natl Inst Laser Plasma & Radiat Phys POB MG 36 Magurele 077125 Romania

Within the past decade, various experimental and theoretical investigations have been performed in the field of high-order harmonics generation (HHG) by means of femtosecond (fs) laser pulses interacting with laser produced plasmas. Numerous potential future applications thus arise. Beyond achieving higher conversion efficiency for higher harmonic orders and hence harmonic power and brilliance, there are more ambitious scientific goals such as attaining shorter harmonic wavelengths or reducing harmonic pulse durations towards the attosecond and even the zeptosecond range. High order harmonics are also an attractive diagnostic tool for the laser-plasma interaction process itself. Particle-in-Cell (PIC) simulations are known to be one of the most important numerical instruments employed in plasma physics and in laser-plasma interaction investigations. The novelty brought by this paper consists in combining the PIC method with several machine learning approaches. For predictive modelling purposes, a universal functional approximator is used, namely a multi-layer perceptron (MLP), in conjunction with a self-organizing map (SOM). The training sets have been retrieved from the PIC simulations and also from the available literature in the field. The results demonstrate the potential utility of machine learning in predicting optimal interaction scenarios for gaining higher order harmonics or harmonics with particular features such as a particular wavelength range, a particular harmonic pulse duration or a certain intensity. Furthermore, the author will show how machine learning can be used for estimations of electronic temperatures, proving that it can be a reliable tool for obtaining better insights into the fs laser interaction physics.

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

来源：评论

学校读者我要写书评

暂无评论

NaNet-10: a 10GbE network interface card for the GPU-based low-level trigger of the NA62 RICH detector

引用

JOURNAL OF INSTRUMENTATION 2016年第3期11卷

作者： Ammendola, R. Biagioni, A. Fiorini, M. Frezza, O. Lonardo, A. Lamanna, G. Lo Cicero, F. Martinelli, M. Neri, I. Paolucci, P. S. Pastorelli, E. Piandani, R. Pontisso, L. Rossetti, D. Simula, F. Sozzi, M. Tosoratto, L. Vicini, P. Ist Nazl Fis Nucl Sez Roma Tor Vergata Via Ric Sci 1 I-00133 Rome Italy Ist Nazl Fis Nucl Sez Roma Sapienza Ple Aldo Moro 2 I-00185 Rome Italy Univ Ferrara Via Saragat 1 I-44122 Ferrara Italy Ist Nazl Fis Nucl Sez Ferrara Polo Sci & Tecnol Via Saragat 1 I-44122 Ferrara Italy CERN CH-1211 Geneva 23 Switzerland Ist Nazl Fis Nucl Lab Nazl Frascati Via E Fermi 40 I-00044 Rome Italy Ist Nazl Fis Nucl Sez Pisa Via F Buonarroti 2 I-56127 Pisa Italy NVIDIA Corp 2701 San Tomas Expressway Santa Clara CA 95050 USA

A GPU-based low level (L0) trigger is currently integrated in the experimental setup of the RICH detector of the NA62 experiment to assess the feasibility of building more refined physics-related trigger primitives and thus improve the trigger discriminating power. To ensure the real-time operation of the system, a dedicated data transport mechanism has been implemented: an FPGA-based Network Interface Card (NaNet-10) receives data from detectors and forwards them with low, predictable latency to the memory of the GPU performing the trigger algorithms. Results of the ring-shaped hit patterns reconstruction will be reported and discussed.

关键词： data processing methods Trigger concepts and systems (hardware and software) Online farms and online filtering

来源：评论

学校读者我要写书评

暂无评论

USB 3.0 readout and time-walk correction method for Timepix3 detector

引用

JOURNAL OF INSTRUMENTATION 2016年第12期11卷

作者： Turecek, D. Jakubek, J. Soukup, P. ADVACAM Sro Balkane 2075 Prague 13400 Czech Republic Charles Univ Prague Fac Med 1 CAPI Salmovska 3 Prague 12000 2 Czech Republic

The hybrid particle counting pixel detectors of Medipix family are well known. In this contribution we present new USB 3.0 based interface AdvaDAQ for Timepix3 detector. The AdvaDAQ interface is designed with a maximal emphasis to the flexibility. It is successor of FitPIX interface developed in IEAP CTU in Prague. Its modular architecture supports all Medipix/Timepix chips and all their different readout modes: Medipix2, Timepix (serial and parallel), Medipix3 and Timepix3. The high bandwidth of USB 3.0 permits readout of 1700 full frames per second with Timepix or 8 channel data acquisition from Timepix3 at frequency of 320 MHz. The control and data acquisition is integrated in a multiplatform PiXet software (MS Windows, Mac OS, Linux). In the second part of the publication a new method for correction of the time-walk effect in Timepix3 is described. Moreover, a fully spectroscopic X-ray imaging with Timepix3 detector operated in the ToT mode ( Time-over-Threshold) is presented. It is shown that the AdvaDAQ's readout speed is sufficient to perform spectroscopic measurement at full intensity of radiographic setups equipped with nano- or micro-focus X-ray tubes.

关键词： data processing methods Detector control systems (detector and experiment monitoring and slow-control systems,architecture,hardware,algorithms,databases)

来源：评论

学校读者我要写书评

暂无评论

A reconstruction algorithm based on sparse representation for Raman signal processing under high background noise

引用

JOURNAL OF INSTRUMENTATION 2016年第2期11卷

作者： Fan, X. G. Wang, X. F. Wang, X. Xu, Y. J. Que, J. He, H. Wang, X. D. Tang, M. Xiamen Univ Sch Aerosp Engn 422 South Siming Rd Xiamen Peoples R China

Background noise is one of the main interference sources of the Raman spectroscopy measurement and imaging technique. In this paper, a sparse representation based algorithm is presented to process the Raman signals under high background noise. In contrast with the existing de-noising methods, the proposed method reconstructs the pure Raman signals by estimating the Raman peak information. The advantage of the proposed algorithm is its high anti-noise capacity and low pure Raman signal reduction contributed by its reconstruction principle. Meanwhile, the Batch-OMP algorithm is applied to accelerate the training of the sparse representation. Therefore, it is very suitable to be adopted in the Raman measurement or imaging instruments to observe fast dynamic processes where the scanning time has to be shortened and the signal-to-noise ratio (SNR) of the raw tested signal is reduced. In the simulation and experiment, the de-noising result obtained by the proposed algorithm was better than the traditional Savitzky-Golay (S-G) filter and the fixed-threshold wavelet de-noising algorithm.

关键词： data processing methods Pattern recognition, cluster finding, calibration and fitting methods Analysis and statistical methods

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：