Cylinder Mirror Research Articles

The soft X-ray spectromicroscopy beamline BL08U1A upgrade at SSRF.

Beamline BL08U1A is a soft X-ray spectromicroscopy beamline at Shanghai Synchrotron Radiation Facility (SSRF) that exhibits the capabilities of high spatial resolution (30 nm) and high energy resolving power (over 104). As a first-generation beamline of SSRF, owing to its continuous operation over the last ten years, an urgent upgrade of the equipment including the monochromator was deemed necessary. The upgrade work included the overall construction of the monochromator and replacement of the mirrors upstream and downstream of the monochromator. Based on its original skeleton, two elliptically cylinder mirrors were designed to focus the beam horizontally, which can increase the flux density by about three times on the exit slits. Meanwhile, the application of variable-line-space gratings in the monochromator demonstrates the dual functions of dispersing and focusing on the exit slits which can decrease abberations dramatically. After the upgrade of the main components of the beamline, the energy range is 180-2000 eV, the energy resolving power reaches 16333 @ 244 eV and 12730 @ 401 eV, and the photon flux measured in the experimental station is over 2.45 × 109 photons s-1 (E/ΔE= 6440 @ 244 eV).

Properties of ceramic coatings in engine cylinder liners restoration using combined technology

In the course of vehicle operation with internal combustion engines, due to various reasons, defects occur on the cylinder mirror, resulting in the need for repair work to eliminate them. For non-cylinder blocks most often requires replacement with a new block, which is economically very costly. The technologies of liner restoration are very diverse and their application depends on the available equipment and material of the liner. The aim of the work is to develop a new combined technology for the restoration of liners and cylinder blocks regardless of the material for their manufacture. As a technology of restoration of the geometry of the mirror of the liner the method of cold gas dynamic spraying with the use of aluminum powder is considered. Subsequent application of the plasma electrolytic oxidation (PEO) technology makes it possible to obtain on the mirror a ceramic coating with thickness of 80-100 microns, which is sufficient for long-term operation of the internal combustion engine. On the basis of GZ-195N liner the technology of cylinder mirror restoration was worked out and the process of plasma electrolytic oxidation (PEO) was carried out. Research has shown that the hardening of the coating occurs to the depth of 100 microns required by the technology. The wear resistance of the coating exceeds the wear resistance of the reference sample, its wear factor is 1.27 times less than that of the reference pair. The possibility of using the technology of aluminum coating by cold spray on any metal makes the combined technology of cylinder liner repair applicable to achieve the desired result - to restore the performance of the cylinder block or liner and increase their wear resistance. The obtained positive results require the development of industrial technology of combined coating and experimental testing on a running engine.

New technological solutions for restoring the inner surface of hydraulic cylinders

Relevance. Agricultural machines widely use hydraulic cylinders for various auxiliary and working movements. Operation in harsh field conditions leads to the failure of the hydraulic cylinder mirror and, as a result, to the loss of force on the cylinder rod. The development of technological solutions for the restoration of the inner surface as a more appropriate solution in repair production is relevant.Methods. Studies of the heat flow using the “Fluke Ti32” thermal imager and ofthe influence of gas-dynamic spraying (GDS) modes on the adhesive and cohesive strength when using a new design of the nozzle part of the GDS equipment were carried out.Results. The suitability of usage of new nozzle design for GDS in order to restore the inner surface of the hydraulic cylinder body has been established. The elongated and curved nozzle for installations of the “Dimet” type practically does not change the temperature regime of spraying. The adhesive and cohesive strength of the coatings obtained with the new nozzle design is sufficient to operate under conditions characteristic of the inner surface of the hydraulic cylinder body.

Study of characteristics of the pair "cylinder mirror — piston ring" of the internal combustion engine

Comparative studies of the coefficient of friction and wear of the pair "cylinder mirror — piston ring" of the internal combustion engine using ceramic coatings obtained by micro-arc oxidation technology (MDO). Practical tests have shown the effectiveness of the use of MDO technology for the cylinder mirror to reduce the coefficient of friction and reduce the wear of the piston ring. The conclusion is made about the necessity of introduction of the considered technology into serial production of engines.

Beam-down linear Fresnel reflector: BDLFR

This paper presents a novel linear solar concentrating system named BDLFR, acronym of Beam-Down Linear Fresnel Reflector. A BDLFR system consists of a primary LFR array reflecting sunlight into a secondary hyperbolic –or elliptic– cylinder mirror that beams-downs reflected rays to its secondary focal line at ground level, where the receiver is placed. A model based on vector notation –and validated against SolTrace– predicts the optical behavior of BDLFR and generates layouts to avoid blockings. The edge ray approach is utilized to determine receiver aperture widths. As a function of beam-down curvature ratio, the BDLFR configurations that maximize solar collection are found out. Concentration ratios about 80 are reached with a tertiary re-concentrator (CPC) coupled to the receiver aperture.

Ex situ metrology and data analysis for optimization of beamline performance of aspherical pre-shaped x-ray mirrors at the advanced light source.

Super high quality aspherical x-ray mirrors with a residual slope error of ∼100 nrad (root-mean-square) and a height error of ∼1-2 nm (peak-to-valley), and even lower, are now available from a number of the most advanced vendors utilizing deterministic polishing techniques. The mirror specification for the fabrication is based on the simulations of the desired performance of the mirror in the beamline optical system and is normally given with the acceptable level of deviation of the mirror figure and finish from the desired ideal shape. For example, in the case of aspherical x-ray mirrors designed for the Advanced Light Source (ALS) QERLIN beamline, the ideal shape is defined with the beamline application (conjugate) parameters and their tolerances. In this paper, we first discuss an original procedure and dedicated software developed at the ALS X-Ray Optics Laboratory (XROL) for optimization of beamline performance of pre-shaped hyperbolic and elliptical mirrors. The optimization is based on results of ex situ surface slope metrology and consists in minimization of the mirror shape error by determining the conjugate parameters of the best-fit ideal shape within the specified tolerances. We describe novel optical metrology instrumentation, measuring techniques, and analytical methods used at the XROL for acquisition of surface slope data and optimization of the optic's beamline performance. The high efficacy of the developed experimental methods and data analysis procedures is demonstrated in results of measurements with and performance optimization of hyperbolic and elliptical cylinder mirrors designed and fabricated for the ALS QERLIN beamline.

Therapeutic effectiveness of toric implantable collamer lens in treating ultrahigh myopic astigmatism

With a rapid increase in the prevalence of Ultra-High Myopic Astigmatism (UHMA), especially in the youth, there have been many studies on visual correction. In our study, we investigated the clinical value of the Toric Implantable Collamer Lens (TICL) in UHMA. We conducted a retrospective study between 2011 and 2013. TICL implantation was performed on fifteen UHMA patients (30 eyes), and all these patients were regularly followed up for 12 months. The preoperative and postoperative data, including Uncorrected Visual Acuity (UCVA), Best Corrected Visual Acuity (BCVA), Intraocular Pressure (IOP), and corneal endothelial counts, were all analysed using the paired-sample t-test. The 12-month spherical mirror (SPH) of the surgical eye was -0.25~+0.25 D, and the Cylinder mirror (CYL) was 0~-0.50 D. Twenty patients exhibited an increase in UCVA by one level in comparison to the preoperative BCVA, amounting to a 66.7% increase; 20.0% of patients exhibited an increase in UCVA by two levels. A comparison between the preoperative and postoperative IOP showed no statistically significant difference. No difference was also found in mean corneal endothelial counts before and after the operation. A decrease in visual acuity was observed in one eye at the 3rd-month of review; this was corrected by TICL position adjustment. Precisely measuring the preoperative parameters, selecting the appropriate TICL, more thoroughly aspirating sodium hyaluronate intraoperatively, and maintaining a stable IOP were important for maintaining the effectiveness, safety and stability of TICL in treating UHMA.

Mutual optical intensity propagation through non-ideal mirrors.

The mutual optical intensity (MOI) model is extended to include the propagation of partially coherent radiation through non-ideal mirrors. The propagation of the MOI from the incident to the exit plane of the mirror is realised by local ray tracing. The effects of figure errors can be expressed as phase shifts obtained by either the phase projection approach or the direct path length method. Using the MOI model, the effects of figure errors are studied for diffraction-limited cases using elliptical cylinder mirrors. Figure errors with low spatial frequencies can vary the intensity distribution, redistribute the local coherence function and distort the wavefront, but have no effect on the global degree of coherence. The MOI model is benchmarked against HYBRID and the multi-electron Synchrotron Radiation Workshop (SRW) code. The results show that the MOI model gives accurate results under different coherence conditions of the beam. Other than intensity profiles, the MOI model can also provide the wavefront and the local coherence function at any location along the beamline. The capability of tuning the trade-off between accuracy and efficiency makes the MOI model an ideal tool for beamline design and optimization.

An end pumped all internal reflection small-sized slab picosecond laser amplifier

An end pumped all internal reflection small-sized slab picosecond laser system amplifier is proposed and demonstrated based on the common Nd:YAG crystal. A cylinder lens is introduced to pre-compensate for the one-dimensional thermal effect caused by the high power pumping laser. The maximum output powers of 6.6 and 6.3 W are obtained at the absorbed pumping power of 25 W without and with a cylinder mirror, and the corresponding optical conversion efficiencies are about 10.4% and 9.3% respectively. The measured M2 factors along the slow and fast axes are 1.71 and 2.47 respectively. The instability of the maximum output laser is below 0.8% (RMS) within measuring time up to 15 min. It is demonstrated that the all internal reflection slab can support long enough optical gain distance to realize the signal laser amplification for the newly developed crystal even with small size and low doped concentration.

Temporal contrast improvement based on the self-diffraction process with a cylinder mirror

A cylinder reflective mirror was used to increase incident pulse energy to multi-millijoules in the research of temporal contrast enhancement based on a self-diffraction (SD) process. A 170 μJ first-order SD pulse with temporal contrast improved by 4 orders of magnitude was obtained when incident pulse energy was 5.1 mJ. In order to improve energy-conversion efficiency, a 67/33 beam splitter was used to replace the original 50/50 one. A 265 μJ first-order SD signal was achieved without damage of the glass plate at 3.7 mJ input pulse energy with an energy-conversion efficiency of about 7.1%. The generated SD pulse is expected to be used as the seed of high-contrast and high-power laser systems.

X-ray collimation by the parabolic cylinder mirror in SPring-8/BL29XUL.

A combination of plane and threefold-shape X-ray mirrors was installed in SPring-8 BL29XUL. The second mirror has parabolic cylinder surfaces that collimate X-rays in the vertical direction. A performance test was conducted, yielding highly collimated 8 keV photon beams with an effective angular divergence of 0.4 µrad, below only 5% of that of the original beams. The double-mirror system preserved 70% of the total incident flux and nearly tripled the flux density at 988 m from the light source. The values of the observations were almost similar to those of our ray-tracing simulation. Based on the results a discussion of future prospects of the mirror system is included.

Reconstruction of Wide FOV Image from Hyperbolic Cylinder Mirror Camera

Abstract In order to contain as much information as possible in a single image, a wide FOV(Field-Of-View) imaging system is required. The catadioptric imaging system with hyperbolic cylinder mirror can acquire over 180 degree horizontal FOV realtime panorama image by using a conventional camera. Because the hyperbolic cylinder mirror has a curved surface in horizontal axis, the original image acquired from the imaging system has the geometrical distortion, which requires the image processing algorithm for reconstruction. In this paper, the image reconstruction algorithms for two cases are studied: (1) to obtain an image with uniform angular resolution and (2) to obtain horizontally rectilinear image. The image acquisition model of the hyperbolic cylinder mirror imaging system is analyzed by the geometrical optics and the image reconstruction algorithms are proposed based on the image acquisition model. To show the validity of the proposed algorithms, experiments are carried out and presented in this paper. The experimental results show that the reconstructed images have a uniform angular resolution and a rectilinear form in horizontal axis, which are natural to human.

Performance optimization of a bendable parabolic cylinder collimating X-ray mirror for the ALS micro-XAS beamline 10.3.2.

The Advanced Light Source (ALS) beamline (BL) 10.3.2 is an apparatus for X-ray microprobe spectroscopy and diffraction experiments, operating in the energy range 2.4-17 keV. The performance of the beamline, namely the spatial and energy resolutions of the measurements, depends significantly on the collimation quality of light incident on the monochromator. In the BL 10.3.2 end-station, the synchrotron source is imaged 1:1 onto a set of roll slits which form a virtual source. The light from this source is collimated in the vertical direction by a bendable parabolic cylinder mirror. Details are presented of the mirror design, which allows for precision assembly, alignment and shaping of the mirror, as well as for extending of the mirror operating lifetime by a factor of ∼10. Assembly, mirror optimal shaping and preliminary alignment were performed ex situ in the ALS X-ray Optics Laboratory (XROL). Using an original method for optimal ex situ characterization and setting of bendable X-ray optics developed at the XROL, a root-mean-square (RMS) residual surface slope error of 0.31 µrad with respect to the desired parabola, and an RMS residual height error of less than 3 nm were achieved. Once in place at the beamline, deviations from the designed optical geometry (e.g. due to the tolerances for setting the distance to the virtual source, the grazing incidence angle, the transverse position) and/or mirror shape (e.g. due to a heat load deformation) may appear. Due to the errors, on installation the energy spread from the monochromator is typically a few electron-volts. Here, a new technique developed and successfully implemented for at-wavelength (in situ) fine optimal tuning of the mirror, enabling us to reduce the collimation-induced energy spread to ∼0.05 eV, is described.

광각 파노라마 영상획득 방법

한 장의 영상에 보다 많은 영상정보를 담기 위해서는 넓은 시야각이 필요하다. 넓은 시야각을 갖는 영상은 보안, 감시, 원격화상회의, 이동로봇 등의 산업분야에서 사용된다. 본 논문에서는 광각의 파노라마 영상을 획득하기 위해 쌍곡면 실린더형 반사체를 이용한 영상획득 방법을 제안한다. 일반적인 응용 예에서 수직화각 보다 수평화각이 중요하므로 수직방향으로는 평면거울과 같고, 수평방향으로 쌍곡선 형태를 갖는 실린더형 반사체를 설계하였다. 광학적 성능 분석을 위해 광선추적법을 통해 본 쌍곡면 실린더형 반사체 영상계의 영상획득 모델을 구하였으며, 쌍곡면 실린더형 반사체를 실제 제작하였고, 영상 실험을 통해 광각 영상획득 성능을 검증하였다. 제안하는 영상 시스템은 기존 방법에 비해 경제적이며, 별도의 영상처리 없이 수평화각 210도에 이르는 광각의 실시간 파노라마 영상을 획득할 수 있었다. 【Wide FOV(Field-of-View) is required to contain much more visual information in a single image. The wide FOV imaging system has many industrial applications such as surveillance, security, tele-conference, and mobile robots. In order to obtain a wide FOV panorama image, an imaging system with hyperbolic cylinder mirror is proposed in this paper. Because the horizontal FOV is more important than the vertical FOV in general, a hyperbolic cylinder mirror is designed in this paper, that has a hyperbolic curve in the horizontal surface and is the same as a planar mirror in the vertical axis. Imaging model of the proposed imaging system is presented by ray tracing method and the hyperbolic cylinder mirror is implemented. The imaging performance of wide FOV is verified by experiments in this paper. This imaging system is cost-effective and is possible to acquire a wide panorama image having 210 degree horizontal FOV in real-time without an extra image processing.】

Effect of curve groove on the spectral resolution for soft X-ray holographic flat-field gratings

The soft X-ray spectrograph is an important instrument for plasma diagnostics. As the core optical element of spectrograph, holographic flat-field grating is fabricated by aspheric wave-front recording optics, so grooves on the surface are curve. The curve grooves of the grating would affect the spectral image properties, thus influencing spectral resolutions. In the design of recording optics, only the groove density distribution on the surface in meridian line should be guaranteed, so optimized recording optics is not unique. Thus gratings with different curvatures of grooves but with expected groove density distribution could be obtained. For holographic flat-field gratings used in a 0.8-6 nm region, we analyze the influences of different curve grooves on the spectral image by ray tracing, and find that the almost straight grooves which are obtained by means of cylinder mirror can obtain the better spectral images. The theoretical results show that the spectral resolutions of grating with almost straight grooves are obviously improved compared with curve grooves, the theoretical spectral resolutions increase from 626 to 953 at 3 nm and from 635 to 1222 at 5 nm, respectively.

Regge Poles in Neutron Scattering by a Cylinder

We establish asymptotic expressions for the positions of Regge poles for cold neutron scattering on mesoscopic cylinder mirror as well as for theS-matrix residuals. We outline the correspondence between Regge poles and near-surface quasi-stationary neutron states. Such states are of practical importance for studying subtle effects of neutron-surface interaction.

Experiment of Si target ablation with soft X-ray laser operating at a wavelength of 46.9 nm

We successfully ablated the Si target by the focused beam of capillary-discharge pumped laser at 46.9nm. The laser of ∼50μJ was focused by the sagittal surface of the cylinder mirror at grazing incidence. Fluences of the focused beam were varied by changing the distance between the mirror and target, and clear ablation patterns were obtained. The shapes of the patterns were consistent with the results simulated by ZEMAX software. The irradiance of the focal spot was simulated as well. Each pattern was ablated by 200 shots and the sampling distance between any two contiguous ablation positions was 0.7cm. The peak value of energy density of the focal spot was estimated to be 7.48×10−3J/cm2. According to the ablation pattern, the focal point of the mirror was determined. The experiment provides reliable data and focusing method for interaction of X-ray laser with solid target.

Trial on having Students Acquire Wide Ranging Analytical Skill and Research Attitude in a Short Period After Becoming Senior in University

This paper describes the effectiveness of an advanced pre-graduation work seminar for proceeding to final graduation research by assigning fourth-year students topics based on the history of technology. This seminar aims the development of student′s capability for taking actions by their own thought who has no time to commence full scale graduation research because of employment activities. In fiscal 2008, 5 students are provided with advanced instruction how to approach research work in numerical analysis by given a theme of cylindrical mirror anamorphoses. The reason to select anamorphoses as theme is that a cylindrical mirror is easier to arrange for a mirror play. The geometry of cylindrical mirror anamorphoses is not really quite complex, but simple approximation methods have been used to draw images spread out in a circular region around the mirror. Although this method gives images that are a little close to being mathematically correct, it is necessary for the students learning engineering to understand the mirror anamorphoses from a view point of optics. This paper discusses the fundamental mirror optics and perspective drawing technique, and then refers to a further discussion about engineering education of a history of optics toys and computer simulation technique of cylinder mirror anamorphosis.

X-ray intensity distribution in the image plane of elliptic multilayer mirrors

The x-ray intensity distribution in the image plane of a multilayer elliptical cylinder and ellipsoid-revolution mirrors was studied Analytical expressions for calculating this distribution were derived as a function of the size of the source, its position with respect to the mirror, and the microroughness of the multilayer structure.

High sensitivity IR spectroscopic methods of self-assembling monolayers (SAM) measurements

New systems of coupling the FTIR spectrum signal amplification, mainly for self-assembling monolayers (SAMs) investigation, were developed. These systems based on hollow waveguide (HW) or half cylinder mirror, which have negligible attenuation in the mid infrared; enable to obtain high signal sensitivity of the samples absorption due to the very high signal to noise ratio. This has lead more detailed characterization of the SAMs molecular structure and its modifications. In addition, a linear dependence of the signal on the number of IR radiation rays incidents on length of HW, which has resulted in simple interpretation of results, was obtained.