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Issue 11 ， 2017
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Fabrication of diffractive X-ray optics and their performance characterization
Abstract：The present status and recent advances in nanofabrication of X-ray diffractive lenses in domestic and overseas were reviewed. The research and achievements of in the past three years by author's group were introduced. For the key technology of diffractive lenses, the basic processes of electron beam lithography for large aspect ratio profiles in resists was established. By combing with Au electroplating, a solid technical background for nanoscale zone plates was successfully built up and applied to the fabr Keywords：diffractive X-ray optics;zone plate;electron beam lithography;nanofabrication;condenser;Siemens star;synchrotron radiation source- 82
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Published：2020-07-07 -
DW/Si multilayer for eXTP mission
Abstract：For the requirements of an embedded focused imaging telescope in eXTP (enhanced X-ray Timing and Polarization satellite) for W/Si multilayers on a cylindrical mirror, W/Si multilayers were fabricated at a grazing incident angle of 0.5° and working range of 1-30 keV, and multilayer fabrication technologies were optimized. Firstly, separator plates and masks were mounted to collimate the sputtering particles to optimize different background pressures and working gas pressures in the deposition process and to Keywords：eXTP mission;interfacial roughness;thickness uniform;cylindrical mirror;depth-graded multilayer- 88
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Published：2020-07-07 -
Fabrication and focusing test of hard X-ray zone plates with high aspect ratio
Abstract：The high-resolution hard X-ray ( > 2 keV) Fresnel zone plates with high density and high aspect ratio was fabricated for Synchrotron Radiation Light Source. The electron beam lithography and the fabrication of hard X-ray zone plates were simulated with Monte Carlo method by combining high accelerating voltage (100 kV) with Si 3N4 self-standing film to reduce the backscattering. The simulation result shows that Si3N4 self-standing film substrate effectively reduces backscattering when electrons propagate Keywords：hard X-ray zone plates;electron beam lithography;high aspect-ratio zone plate;self-standing film- 73
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Published：2020-07-07 -
KB mirror system of X-ray photo-emission electron microscope beamline
Abstract：A high accuracy micro-focusing system was designed to improve the light spot focusing quality of the X-ray beam-line for Photo-emission Electron Microscope (PEEM) in Shanghai Synchrotron Radiation Facility(SSRF). The layout of PEEM beam-line of the SSRF was introduced and basic parameters of optics of the micro-focusing system were presented. Two Kirkpatrick-Baez mirrors (KB mirror) were adopted to finish the design of micro-focusing system. The design scheme of a key component-posture adjusting mechanism i Keywords：synchrotron radiation;Photo-emission Electron Microscope(PEEM);X-ray microscopy;KB mirror;structure design- 81
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Published：2020-07-07 -
Fabrication of PMMA hard X-ray compound Kinoform lenses
Abstract：To improve the focusing performance of hard X-ray focusing elements, a hard X-ray Compound Kinoform Lens (CKL) based on Polymethyl methacrylate (PMMA) with a depth of 60 μm is fabricated by LIGA(Lithographie, Galvanoformung, Abformung)technology, and its excellent morphology is obtained. The main structure of CKL is a narrow pattern with a few micron widths, including the curve and the rectangular surfaces, and the width of the narrowest pattern is only 2 μm. The fabrication of the CKL is divided into three Keywords：Kinoform lens;x-ray focusing lens;LIGA technology;Polymethyl Methacrylate(PMMA)- 61
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Published：2020-07-07 -
Optical constant of MgF2 coatings for Al/MgF2 mirror in vacuum ultraviolet region
Abstract：As the optical constant of MgF2 over-coated Al mirror effects its optical performance greatly, this paper explores the method to obtain the optical constant. Three Al/MgF2 mirror samples covered by MgF2 coatings with different thicknesses were deposited on B270 substrates at room temperature by thermal evaporation method. The layer structures of the samples such as the thickness and the roughness were characterized by the grazing incidence X-ray reflectometry. The reflectivities of the samples at a incidenc Keywords：vacuum ultraviolet;mirror;protective layer;optical constant;Fresnel formulas;thermal evaporation- 78
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Published：2020-07-07 -
Real-time X-ray diffractometry for lattice response measurement under gas-gun loading
Abstract：The microscopic response measurement of material dynamics was researched experimentally under the loading conditions of gas gun loading. Based on a flash X-ray source with the half width of 25 ns, a real-time X-ray diffraction diagnostic system was developed by using integral record devices. The measuring principle of X-ray diffraction system was introduced. Due to the duration of shocked state in the probed region and the output timing jitter of the X-ray source, the difficulty of system synchronization fo Keywords：real-time X-ray diffraction;kinetics of material;microscopic response;lattice deformation;gas-gun loading- 76
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Published：2020-07-07 -
Cleaning of carbon contamination on multilayer optics of EUVL
Abstract：This paper focuses on the reflectivity decrease of reflective elements caused by the carbon contamination deposited on multilayers during EUV(Extreme Ultraviolet) lithography working and emphasizes the clear method of carbon contamination deposited on multilayers. The process of carbon contamination deposited on multilayers was elucidated and the damage of carbon contamination on the multilayers was introduced briefly. Several kinds of cleaning methods for carbon contamination deposited on multilayers were Keywords：extreme ultraviolet lithography;carbon contamination;cleaning technologies;multilayers- 87
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Published：2020-07-07 -
Absolute measurement of photon flux for synchrotron radiation hard X-rays
Abstract：The photon flux of the synchrotron radiation hard X-rays was measured in Beijing Synchrotron Radiation Facility (BSRF) using a free-air ionization chamber. Absolute air-kerma can be obtained with the free-air ionization chamber. The photon flux was calculated based on the relation between air-kerma and flux in the fundamental quantities and units for ionizing radiation. Because the photon flux changes over time during the measurement, an online monitoring system was applied, and the uncertainty of which is 0.03%. The air attenuation correction factor and ion recombination correction factor were measured at 15 keV synchrotron radiation X-rays. The measurement results show that the absolute air-kerma rate at 15 keV synchrotron radiation X-rays is 0.239 Gy/s, accordingly, the photon flux of the source is 5.28×109 photons/s, the relative uncertainty is 0.68%.Keywords：synchrotron radiation hard X-rays;absolute measurement;free air ion chamber;air-kerma;photon flux- 150
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Published：2020-07-07 -
Optimum design and test experiments of spherically bent crystal imaging
Abstract：In order to achieve high spatial resolution and narrow spectral bandwidth imaging of laser plasma in updated SG-Ⅱ laser facility, the relations of the imaging quality of spherically bent crystal with image distance, Bragg angle and backlit size were discussed. First, spherically bent crystal imaging at diverse image distances, Bragg angles and backlit sizes were studied with a ray tracing program X-LAB. Then, a test experiment was carried out by using X-ray tube device. The results show that better two-dimension image could be obtained at the image distance of equal resolution of two dimensions, and larger the Bragg angle is, better the imaging is. Furthermore, smaller size of backlit is also helpful to improve the imaging quality. The experiment result agrees well with the expectation, a spatial resolution better than 14 μm in the image of the mesh. The results obtained contribute to the optimization design of the spherically bent crystal imaging system and precision diagnosis of laser plasma.Keywords：X-ray imaging;spherically bent crystal;ray tracing;monochromatic imaging;plasma- 87
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Published：2020-07-07 -
Investigation on microstructures and interfaces of NiC/Ti neutron multilayers
Abstract：NiC/Ti neutron supermirror plays a key role in improving the capability of neutron optics. In order to improve the performance of the neutron supermirror, a study in microstructures and interfaces of NiC/Ti multilayers with varied NiC layer thickness was presented. The thickness, interface roughness and crystalline state of NiC/Ti multilayers were represent by Grazing incidence X-ray reflectivity and X-ray diffraction, respectively. The study results indicate that the NiC-on-Ti interface roughness was almos Keywords：magnetron sputtering;NiC/Ti multilayers;microstructure;interface roughness- 81
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Published：2020-07-07 -
Hard X-ray imaging based on CCD and CsI scintillator
Abstract：In consideration of the working characteristics of a Charge Coupled Devices(CCD), an imaging detector based on CCD and CsI scintillator was presented by using flexible exposure control and multi-frame superpositioning techniques to improve the detection efficiency of hard X-ray. An experimental platform was built, in which a nickel collimator based on a micromachining techniques was adopted as the imaging spatial target. In the experiment, the 55Fe X-ray source was adopted for direct imaging of CCD itself. Keywords：X-ray imaging;Charge Coupled Device(CCD);CsI scintillator;spatial resolution- 96
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Published：2020-07-07 -
Determination of parameters of X-ray source based on single-bounce ellipsoidal monocapillary X-ray condenser
Abstract：To exactly characterize X-ray light resource parameters, a measuring method for the focal spot size and focal depth of an X-ray source was proposed by using a single-bounce ellipsoidal monocapillary X-ray condenser (SBEMXRC). The SBEMXRC was a kind of X-ray reflective imaging optics and characterized by its single total reflection imaging capability. The universal relationship among the focal spot size of the X-ray source, image size of focal spot of the X-ray source and the slope errors of the SBEMXRC was Keywords：single-bounce ellipsoidal monocapillary X-ray condenser;X-ray sources;focal spot size and focal depth of X-ray source- 111
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Published：2020-07-07 -
Synchrotron radiation X-ray fluorescence spectrometer based on three crystals and multi-axis linkage
Abstract：To meet the requirements of the X-ray fluorescence spectrometer in Shanghai Synchrotron Radiation Facility(XAFS) for sensitivity and resolution, a synchrotron radiation X-ray fluorescence spectrometer was proposed based on three-crystal and multi-axis linkage. In experiments, the X-ray was provided by a double crystal monochromator, the dispersion structure was made of three concave crystals and these crystals formed an intersectant Rowland circle in the vertical plane to achieve the fluorescent analysis. M Keywords：X-ray fluorescence spectrometer;high resolution fluorescence spectrometer;three crystals;multi-axis linkage;EPICS system- 80
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Published：2020-07-07
X-ray Optics
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Improvement of resonant frequency characteristics of photoelectric tracking system with new bearing structure
Abstract：The structure of a typical photoelectric tracking system was analyzed and a method to improve the resonant frequency of mechanical structure was proposed to improve the tracking speed of the photoelectric tracking system. The structure of the vertical bearing of a typical tracking frame was researched, and it pointed out that the torsional stiffness of the system was limited by the movement of a one-way thrust bearing along axial direction. Then, a structure of double thrust bearing combined with centering Keywords：photoelectric tracking system;speed of tracking;mechanical resonant frequency;structure of double thrust bearing- 96
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Published：2020-07-07 -
Analysis of end face damage in lapping for photonic crystal fiber
Abstract：The lapping process for photonic crystal fibers (PCFs) was studied, and the end face damage of the PCFs was discussed. Based on the structure characteristics of the PCFs, a digital simulation model was established by finite element method. Through the simulation of a single grinding hole wall, the occurrence of crack damage under different cutting depths and the effect of damage caused by different grinding grain diameters on the structure of fiber hole wall were analyzed. Finally, the analysis results were Keywords：photonic crystal fiber;fiber end face;lap damage;FEA- 72
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Published：2020-07-07 -
Stiffness and natural frequency of a (2PRR)2+R planar parallel mechanism
Abstract：A novel 5-degree-of-freedom (DOF) hybrid serial-parallel manipulator was proposed. The kinematics of Parallel Mechanism (PM) of the 5-DOF hybrid manipulator was analyzed. The PM is a 3-DOF (one translational DOF and two rotational DOFs) metamorphic planar PM (2PRR)2+R with two different types of configurations:actuation redundancy and kinematic redundancy. Firstly, the kinematics model of the 3-DOF planar PM was established. Then, the stiffness matrix of the planar PM was obtained on the basis of kinematics Keywords：planar parallel mechanism;kinematic redundancy;actuation redundancy;stiffness;natural frequency- 81
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Published：2020-07-07 -
Design of cymbal shape slotted valve based piezoelectric pump
Abstract：The valve inside a piezoelectric pump was easy to be failure when it was suffered too much stress concentration. A cymbal-shape slotted check valve was proposed to reduce the stress concentration of the piezoelectric pump. A valve-based piezoelectric pump was designed by using the cymbal-shape slotted check valve, and the working principle of the cymbal-shape slotted check valve based piezoelectric pump was introduced. The stress of the cymbal-shape slotted diaphragm was analyzed, the output performance of Keywords：cymbal-shaped slotted;valve piezoelectric pump;stress;fluid-solid coupling interaction- 80
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Published：2020-07-07 -
Design of truss framework of multi-mirror optical system for large-scale space infrared camera
Abstract：To meet the requirements of a large-scale space infrared camera for a lighter weight and higher rigidity framework with complex support function, a framework entirely formed by trusses was designed.Then, the feasibility and reliability of the frame were demonstrated by structure analysis, technological test and mechanical test. The framework was combined by 58 carbon fiber struts and 21 joints to form the main support structure of the camera. It could support most of optical modules in circumference distrib Keywords：space infrared camera;truss structure;finite element analysis;process experiment- 80
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Published：2020-07-07 -
High precision automatic measurement for alignment of camera and star-sensor in GF-2
Abstract：To alignment the posture between the camera and the star-sensor on the GF-2 satellite, a high precision automatic measurement system was established. For the measuring system, a high precision measurement algorithm based on multi-sensor fusion, an automatic measurement plane based on design data, and a cube mirror normal measurement method based on geometric figure recognition were investigated. The system was mainly constituted by a double column guideway system, a precision turntable, and an autocollimati Keywords：satellite assembly;posture matrix;angle measurement;autocollimation;automatic measurement- 121
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Published：2020-07-07
Micro/Nano Technology and Fine Mechanics
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Ship recognition based on multi-band deep neural network
Abstract：The fusion recognition of multi-band images can extend the application range of recognition systems. A fusion method based on convolutional neural networks (CNN) was explored and designed in this paper. Based on the AlexNet network model, it was extracted that the ship target features of three wave band images concurrently in visible light, Middle Wave Infrared (MWIR) and Long Wave Infrared (LWIR) bands. Then, it performed the feature selection for concatenated three-band eigenvectors by using the mutual in Keywords：target recognition;feature fusion;CNN;multi-spectral images;feature selection;image quality assessmen- 113
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Published：2020-07-07 -
Automatic recognition of micro-expressions action for human lower limb
Abstract：Because the existing motion recognition method couldnot be directly used in human micro-expression action recognition. A spatio-temporal pyramid Weber Local Descriptor (STPWLD) was constructed and an automatic recognition algorithm of human lower limb micro-expression action based on dictionary learning according to characterize human lower limb micro-expression action was designed. With the method, the features of human lower limb micro-expression action was extracted by the STPWLD. Then, the dimensions of Keywords：human lower limb;micro-expression;action recognition;spatio-temporal pyramid weber local descriptor;dictionary learning- 95
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Published：2020-07-07 -
Spacetarget pose estimation based on binary rotational projection histogram
Abstract：To estimate quickly the relative pose of a space target based on point cloud, a Binary Rotational Projection Histogram (BRoPH) feature descriptor was proposed. Firstly, a Local Reference Frame (LRF) for the feature point was established; Then, the density and depth images were generated under different views by rotationally projecting the local surface of feature point, Finally, the multi-scale binary string of the feature point was produced based on the images. For implementing the pose estimation of space Keywords：space target;pose estimation;point cloud register;rotational projection histogram;binary descriptor- 123
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Published：2020-07-07 -
Binary image watermark fusionbased on quantum key true randomness
Abstract：Current watermarking algorithms use mostly pseudo random sequences to generate watermarks. These algorithms emphasize the improvement of imperceptibility and robustness of the watermarking but ignores its safety. To improve the watermarking safety, a new secure communication oriented airspace watermarking algorithm with a tamper locating function was proposed based on the true randomness of quantum key. According to the principle of BB84 protocol, the quantum key with real randomness and absolute security g Keywords：digital watermark;binary image;quantum key;randomness- 104
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Published：2020-07-07
Information Sciences
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