Simulation optical parameters nanowire structures of various shapes.

In this study, three-dimensional fragments of nanowires structures were simulated in which the thread cross sections had a square, triangular and round shape. The theoretical data were compared with the experimental results, described in detail in [1]. The influence of the shape of the filaments on the theoretical course of the reflection curve is also shown.

Стабильные многослойные отражающие покрытия на длину волны lambda(HeI) = 58.4 nm для солнечного телескопа проекта КОРТЕС

Multilayer aluminum-based structures reflecting at λ(HeI) = 58.4 nm were studied. Spectral and angular dependences of the reflection coefficient of these coatings were determined using a laboratory reflectometer and at the ELETTRA and BESSY II synchrotrons. The optical characteristics of multilayer Ru/Al and Mo/Al mirrors with a protective MoSi_2 layer were found to be stable: the absolute change in the reflection coefficient within 18 months of storage in air was no larger than 1.5%. The peak near-normal reflection coefficient for Mo/Al mirrors at 58.4 nm was R = 26.1% with FWHM Δλ_0.5 = 10 nm of the reflection curve.

RESPONSE OF FBG-BONDED GRAPHENE PLATE AT DIFFERENT APPLIED STRESS LOCATION

In this study, the response of a FBG-bonded-graphene plate at different applied stress location is demonstrated. The sensing element utilized for this purpose is a 35.9-mm FBG sensor bonded onto the surface of a graphene plate. The lateral displacement is changed with corresponding increase or decrease in the FBG’s curvature. The change in center wavelength of the reflected spectrum is almost linear, without a significant hysteresis effect. It was also observed that the sensitivity of the FBG changes for location of applied stress. Likewise, the area under the reflection curve is observed to increase with increase in strain level, indicating an increase total power reflected. This is verified by an increase in the voltage output as observed from the oscilloscope.

Analyses the Character of GaAs Photocathode by Diffraction Curve from Spectrophotometer

Transmissivity and reflectivity of GaAs photocathode get from spectrophotometer are measured and analyzed according to various wave bands, so that the corresponding optics parameter is obtained. The typical optics parameter of various GaAs photocathode has been summarized. For blue-light extension photocathode, the diffraction peak will be close to ultraviolet wave band from the reflection curve. The thickness of Active layer film and optimal Si3N4 film on the GaAlAs layer have been acquired. The experimental and analyzed results have shown that the Si3N4 film on the GaAlAs layer should be about 1000A when the the GaAs photocathode got the optimum performance.The thickness of Active layer film should not be too thick to escape of electron and too thin to transfer of photon-electron. The experiment shows that the spectrophotometer can analyze epitaxial material and assist the manufacture of GaAs photocathode.

X-ray Standing Waves in X-ray Specular Reflection and Fluorescence Study of Nano-Films

The analysis of the wavefield intensity distribution connected with X-ray standing wave (XRSW) generation above the mirror surface at total reflection (TR) is presented for a vacuum/film/substrate sample along with experimental examples for organic and inorganic films for cases where the refractive index of the film is greater than that of the substrate. The thickness of an ultra-thin film may be estimated from the value of the XRSW period formed above the film/substrate interface at TR. In some cases, the thickness of an ultra-thin film may be roughly obtained just from the form of the X-ray reflection curve at incident angles smaller than the critical angle of the substrate. It is demonstrated that interference phenomena at TR, leading to waveguide mode formation inside the layered structure and responsible for a modulation of the X-ray reflection and fluorescence angular dependence, can be used for characterization of nano-films.

X-Ray Point Focusing Using Cylindrically Bent Crystals with Modulated Structures for Synchrotron X-Ray Beams

Micron or submicron spatial resolution for x-ray microfluorescence analysis has been pursued using various x-ray point focusing methods,1-4 such as transmission zone plates, tapered capillaries, and Bragg Fresnel lenses. Point focusing using bent crystals does not seem to be a desirable means for achieving a microbeam size, although it is a traditional technique which utilizes perfectly curved crystal surfaces to focus x rays emanating from the source. It is known that point focusing can only be achieved by bending a crystal two dimensionally, which normally introduces imperfections to the crystal since the crystal is an undevelopable surface. Unavoidably, the introduced imperfections will broaden the reflection curve (rocking curve) of the crystal and, in turn, broadens the focal spot size.

SELF-CONSISTENT X-RAY DIFFRACTION PATTERNS OF PERFECT CRYSTAL

We have developed a self-consistent X-ray scattering model for perfect crystal, which leads to obtain diffraction patterns similar to experimental findings. As an application of the model we carried out the calculations for the Si[333] reflection curve.