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Record 37 of
Title:A full aperture backscattering light diagnostic system installed on the Shenguang-III prototype laser facility
Author(s):Xu, Tao(1); Mei, Yu(1); Wei, Huiyue(1); Peng, Xiaoshi(1); Wang, Feng(1); Yang, Dong(1); Liu, Shenye(1); Yan, Yadong(2)
Source: Plasma Science and Technology Volume: 16 Issue: 6 DOI: 10.1088/1009-0630/16/6/05 Published: June 2014
Abstract:A full aperture backscattering light diagnostic system (FABLDS) implemented on the Shen Guang-III Prototype Laser Facility is described in the paper. FABLDS measures both stimulated brillouin scattering (SBS) and stimulated Raman scattering (SRS) with a series of optical detectors. Energy sensors record the integrated energy, and streak cameras coupled with spectrometers measure the temporal spectrum of the backscattering light. This paper provides an overview of the FABLDS and detailed descriptions of the optical path. Special components, including off-axis parabolic mirror, spatial filter and optical light filters, are incorporated along the beam path for purifying the scattering light. Several hohlraum targets were employed, including C5H12 gas-filled targets and empty targets in the experiments. Results presented in the paper indicate that the fraction of backscatter light has been obviously shrinked when the laser is smoothed by continuous phase plates (CPP).
Accession Number: 20142517828550
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Record 38 of
Title:Simulation study of rotating double optical wedge vectoring optics path based on Matlab
Author(s):Guo, Yunzeng(1,2); Yang, Xiaojun(1); Yang, Xiaojun(1); Jia, Haini(1,2); Wang, Haitao(1); Liu, Feng(1); Jiang, Zhi(3)
Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 43 Issue: 3 DOI: Published: March 2014
Abstract:The optical wedge plays a guiding and key role on the processing of high-precision micro-hole drilling by laser pulses. In order to improve the laser micro-hole processing quality, a method was presented to improve the analysis on the impact of the optical wedge on accuracy of laser micro-manufacturing. First the concept of the equivalent of a single wedge vector was proposed. The double wedge vector model was established and analyzed based on the definition of a single wedge vector, and the new method of the vector superposition of the multiple wedges was came up with. Secondly, the simulation software was programmed by using Matlab. The simulation results show the trail of the laser pulses through the double optical wedge. The effect of the quality of the micro-hole caused by the unsynchronization of the motion system is investigated. The deviation quantitative analysis is carried and the formula of calculation the deviation is given. The conclusion is of great value to the performance indicators of designing the controlling system in the high-precision micro-hole drilling by laser pulses.
Accession Number: 20142217774734
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Record 39 of
Title:An improved hough transform algorithm based on pyramid method
Author(s):Ren, Long(1); Liao, Jia Wen(1); Cao, Jian Zhong(1); Wang, Hua(1); Zhao, Xiao Dong(1); Meng, Han(1)
Source: Applied Mechanics and Materials Volume: 543-547 Issue: DOI: 10.4028/www.scientific.net/AMM.543-547.1917 Published: 2014
Abstract:Hough Transform [1] has become a common method in the usage of line detection because of its robustness. It is important in computer vision and image analysis. Usually, the standard Hough transform method(SHT) transform the points in image space into parameter space and vote for all the possible patterns passing through that point. But, there are two serious problems in the standard method of line detection. The first is the high computation complexity and the second is the large storage requirements.In order to solve the two problems, this paper raise a fast- Hough transform algorithm base on pyramid algorithm. First of all we need to desample the primitive binary image with n times; and execute the Hough transform in the nth level image to get the parameter of straight line in this image, which is used in the n-1 level image. Finally we can get the parameter of lines in the primitive image. Experiments show that this method can extremely reduces the computational time. ? (2014) Trans Tech Publications, Switzerland.
Accession Number: 20141717625024
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Record 40 of
Title:Conservation law of surface roughness in single point diamond turning
Author(s):Zong, W.J.(1); Huang, Y.H.(2); Zhang, Y.L.(3); Sun, T.(1)
Source: International Journal of Machine Tools and Manufacture Volume: 84 Issue: DOI: 10.1016/j.ijmachtools.2014.04.006 Published: September 2014
Abstract:In this work, a comprehensive model is established to predict the surface roughness achieved by single point diamond turning. In addition to the calculation of the roughness components in relation to the kinematics and minimum undeformed chip thickness, the newly developed model also takes the effects of plastic side flow and elastic recovery of materials as machined into account. Moreover, the 'size effect' has also been successfully integrated into the model, i.e. an inflection point appears in the trend line of predicted surface roughness as the ratio of maximal undeformed chip thickness to cutting edge radius (hDmax/rn) is equal to one unit. Face turning experiments validate that the maximal prediction error is only 13.35%. As the ratio of hDmax/rn is higher than one unit, both the prediction and experiments reveal that a conservation law exists in diamond turned surface roughness, owing to the competitive effects of kinematics, minimum undeformed chip thickness, plastic side flow and elastic recovery of materials on surface formation. Under the conservation law, the freedom control for an invariable surface roughness can be fulfilled in response to a quantitative ratio of hDmax/rn, either through an accurate configuration of feed rate and depth of cut with fixed tool nose radius and cutting edge radius, or by a reasonable selection of tool nose radius and controlled cutting edge radius with designed feed rate and depth of cut. ? 2014 Elsevier Ltd.
Accession Number: 20142117750793
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Record 41 of
Title:Application of FIR real-time filtering in fiber-optic current sensor
Author(s):Li, Yuan Yuan(1,2); Xu, Jin Tao(2); Cao, Hui(2); Yang, Xiao Jun(2)
Source: Applied Mechanics and Materials Volume: 568-570 Issue: DOI: 10.4028/www.scientific.net/AMM.568-570.590 Published: 2014
Abstract:When Fiber-Optic Current Sensor(FOCS) measures the grid's small current, FOCS's output contains large noise due to the environment and components' inherent noise, which results in lower accuracy. In order to improve the small current's accuracy, a system of signal processing base on FIR real-time filtering was adopted. This text introduced the window functions' features and filtering system aiming at the FOCS's output was proposed. This system can adjust filter coefficient conveniently according to the output's character. By the AC experiment under room temperature, the result proves that the SNR of FOCS's output signal is improved by filtering and the current error ratio meets 0.2s class. ? (2014) Trans Tech Publications, Switzerland.
Accession Number: 20142717908419
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Record 42 of
Title:Welcome from the program committee chairs
Author(s):Li, Xuelong(1); Cai, Hongming(2)
Source: PIC 2014 - Proceedings of 2014 IEEE International Conference on Progress in Informatics and Computing Volume: Issue: DOI: 10.1109/PIC.2014.6972423 Published: December 2, 2014
Abstract:null
Accession Number: 20145200358207
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Record 43 of
Title:Optical system for full aperture backscatter diagnosis
Author(s):Yan, Ya-Dong(1); He, Jun-Hua(1); Wang, Feng(2); Zhang, Min(1)
Source: Guangxue Jingmi Gongcheng/Optics and Precision Engineering Volume: 22 Issue: 12 DOI: 10.3788/OPE.20142212.3191 Published: December 1, 2014
Abstract:An optical system for full aperture backscatter diagnose was designed for a novel inertial confinement fusion facility. Several key technologies about optical design were discussed. A wedge mirror with low reflectance was used to attenuate the backscatter lights before diagnosis, so the films of optical elements in the diagnostic system were survived after many shots. A telescope optical system was used to reduce the sizes of the beam as well as the sizes of the optical elements, meanwhile the optical path was folded several times by mirrors to shrink the volume of the whole system. The space filter, dichroic filter, optical filters and colored glasses were combined to simultaneously eliminate the stray light. Moreover, a scatter plate was taken to average the signals to ensure the fiber coupler to obtain needed signals including all wavelengths studied. Based on the analysis of imaging beam structures, a lens was designed for the imaging of parabolic mirror, and a camera was used to record the space distribution of scattered lights on the surface of parabolic mirror. The diagnosis system was designed to provide measurements for scattering time, scattering spectrum, near-field imaging, and scattered energy and its whole sizes are 1.9 m×0.9 m×1.5 m. The full aperture backscatter system designed in this paper has potential applications to the new inertial confinement fusion facility. ?, 2014, Chinese Academy of Sciences. All right reserved.
Accession Number: 20150400441431
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Record 44 of
Title:Study of the key aspects in developing kW-level diode lasers for solid state laser pumping
Author(s):Li, Xiaoning(1); Wang, Jingwei(1); Cai, Wanshao(1); Hao, Bei(1); Hou, Dong(1); Liu, Hui(1); Zhang, Pu(1); Liu, Xingsheng(1)
Source: Proceedings - 2014 International Conference Laser Optics, LO 2014 Volume: Issue: DOI: 10.1109/LO.2014.6886212 Published: 2014
Abstract:In this paper, the key aspects, such as thermal management, thermal stress analysis and management, processes development, failure analysis and reliability evaluation, in developing kW-level diode lasers for solid state laser pumping are studied. ? 2014 IEEE.
Accession Number: 20143818166772
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Record 45 of
Title:The preset grating effect for mutually pumped phase conjugator
Author(s):Ma, Lin(1); Kang, Zhihua(2); Zhang, Ninghua(2); Liu, Jifang(2); Shi, Shunxiang(2)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9269 Issue: DOI: 10.1117/12.2071924 Published: 2014
Abstract:Based on the four-wave mixing mechanism and light fanning effect, a mutually pumped phase conjugator(MPPC) model is proposed to analyze the variation of MPPC output response with time for different scattering seed value. It shows that preset grating can enhance the fan light intensity when it satisfies Bragg condition and also can shorten MPPC response time. In experiment the bird-wings MPPC is done with or without the preset grating and the variation of MPPC reflectivity with time is obtained in two cases, and simulation conclusion is in agreement with the experimental result. These results have importance for applications of MPPC on optical heterodyne detection. ? 2014 SPIE.
Accession Number: 20150700527504
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Record 46 of
Title:Design of a high aperture compression ratio, dual-band static Fourier transform imaging spectrometer for remote sensing
Author(s):Zou, Chun-Bo(1,2); Hu, Bing-Liang(2); Li, Li-Bo(1,2); Bai, Qing-Lan(2); Sun, Xin(2); Li, Ran(2); Yang, Jian-Feng(2)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9298 Issue: DOI: 10.1117/12.2083243 Published: 2014
Abstract:A novel dual-band static Fourier transform imaging spectrometer was designed, which was the spatioorally modulated imaging Fourier transform spectrometer based on Sagnac interferometer. The approach represented a simplification and mass reduction over the traditional approach. It could obtain two-dimensional spatial images and one dimensional spectral image in two bands simultaneously. The two bands was separated through a dichroic prism and imaging in two detectors. one band was the visible and near infrared band, with the spectral range 400nm-1000nm and spectral resolution 187.5 wave numbers; the other was the short wave infrared band, with the spectral range 1000nm- 2500nm and spectral resolution 150 wave numbers. To reduce the size of the Interferometer, a high aperture compression ratio telescope system was designed before. The optical aperture was compressed to 1/10, and the volume of interferometer was reduced to 1/1000. For the convenience of engineering implementation, the telescope was composed of two no-aberration object lens: fore-lens and Collimating lens. The two band imaging spectrometers shared the primary lens and the second lens of the fore-lens and use their own collimating lens, interferometers and Fourier transform lens. The collimating lens and the Fourier transform lens of each spectrometer could be designed to the same structural style and parameters. The both spectrometers had a focal length of 1000mm, F number of 5, FOV(field of view) of 1°. Moreover, both image qualities were close to the diffraction limit, the distortion was less than 2%. The advantage of the instrument was that dual band spectral image could be acquired at the same time and the interferometer was miniaturized extremely in the case of unchanged technical indicators. ? 2014 SPIE.
Accession Number: 20150800546061
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Record 47 of
Title:Monte Carlo simulation of HERD calorimeter
Author(s):Xu, M.(1); Chen, G.M.(1); Dong, Y.W.(2); Lu, J.G.(2); Quan, Z.(3); Wang, L.(2); Wang, Z.G.(1); Wu, B.B.(1); Zhang, S.N.(1)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9144 Issue: DOI: 10.1117/12.2055319 Published: 2014
Abstract:The High Energy cosmic-Radiation Detection (HERD) facility onboard China's Space Station is planned for operation starting around 2020 for about 10 years. It is designed as a next generation space facility focused on indirect dark matter search, precise cosmic ray spectrum and composition measurements up to the knee energy, and high energy gamma-ray monitoring and survey. The calorimeter plays an essential role in the main scientific objectives of HERD. A 3-D cubic calorimeter filled with high granularity crystals as active material is a very promising choice for the calorimeter. HERD is mainly composed of a 3-D calorimeter (CALO) surrounded by silicon trackers (TK) from all five sides except the bottom. CALO is made of 9261 cubes of LYSO crystals, corresponding to about 55 radiation lengths and 3 nuclear interaction lengths, respectively. Here the simulation results of the performance of CALO with GEANT4 and FLUKA are presented: 1) the total absorption CALO and its absorption depth for precise energy measurements (energy resolution: 1% for electrons and gammarays beyond 100 GeV, 20% for protons from 100 GeV to 1 PeV); 2) its granularity for particle identification (electron/proton separation power better than 10-5); 3) the homogenous geometry for detecting particles arriving from every unblocked direction for large effective geometrical factor (2sr for electron and diffuse gammarays, >2 m2sr for cosmic ray nuclei); 4) expected observational results such as gamma-ray line spectrum from dark matter annihilation and spectrum measurement of various cosmic ray chemical components. ? 2014 SPIE.
Accession Number: 20150700523550
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Record 48 of
Title:Toward multiscreen social TV with geolocation-aware social sense
Author(s):Hu, Han(1); Wen, Yonggang(2); Luan, Huanbo(1); Chua, Tat-Seng(1); Li, Xuelong(3)
Source: IEEE Multimedia Volume: 21 Issue: 3 DOI: 10.1109/MMUL.2014.2 Published: July/September 2014
Abstract:The increasing popularity of social interactions and geotagged, user-generated content has transformed the television viewing experience from laid-back video watching behavior into a 'lean-forward' socially engaged experience. This article describes a multiscreen, social TV system integrated with social sense via a second screen as a novel paradigm for content consumption. This new application is built upon the authors' cloud-centric media platform, which provides on-demand virtual machines for content platform services, including media distribution, storage, and processing. The media platform is also integrated with a Big Data social platform that crawls and mines social data related to the media content. Specifically, this new social TV approach consists of three key subsystems: interactive TV, social sense, and multiscreen orchestration. Interactive TV implements a cloud-based, social TV system, offering rich social features; social sense discovers the geolocation-aware public perception and knowledge related to the media content; and multiscreen orchestration provides an intuitive and user-friendly human-computer interface to combine the two other subsystems, fusing the TV viewing experience with social perception. The authors have built a proof-of-concept demo over a private cloud at the Nanyang Technological University (NTU), Singapore. Feature verification and performance comparisons demonstrate the feasibility and effectiveness of the proposed approach in transforming the TV viewing experience. ? 2014 IEEE.
Accession Number: 20143218022618
