X-ray tomography as a diagnostic method of X-ray refractive optics

This article describes the application of high-resolution X-ray computed tomography to assess the critical parameters of refractive lenses for X-ray optics that determine the quality of compound optical systems. A microfocus Y. Cheetah X-ray system has been used for three-dimensional visualization of the surface and internal structure of refractive lenses made of high-purity aluminum with geometric apertures of 500 and 1500 μm. A Fein Focus X-ray tube with a focal spot size of less than 2 μm provides the resolution necessary for detecting critical-size microstructure defects in the material of the lens.     

Efficiency in uncertain variational control problems

Neural Computing and Applications - In this paper, considering the applications of interval analysis in various fields (such as artificial intelligence, neural computation, genetic algorithms,...     

Higher-order Hamilton dynamics and Hamilton–Jacobi divergence PDE

This paper, using a non-standard Legendrian duality, investigates the Hamiltonian dynamics and formulates a Hamilton–Jacobi type divergence PDE governed by higher-order Lagrangians.     

Enhanced performance in the deteriorated area of multicrystalline silicon wafers by internal gettering

The deteriorated area of the multicrystalline silicon (mc‐Si) ingots grown by directional solidification, commonly known as the Red Zone, is usually removed before wafering. This area, characterized by poor minority carrier lifetime, is located on the sides, at the top, and the bottom of the mc‐Si ingots. In this study, the effect of internal gettering by oxygen precipitates and structural defects has been investigated on the bottom zone of a mc‐Si ingot. Nucleation and growth of oxygen precipitates as well as low temperature annealing were studied. Photoluminescence imaging, lifetime mapping, and interstitial iron measurements performed by μ‐PCD reveal a considerable reduction of the bottom Red Zone. An improvement of lifetime from below 1 µs to about 20 µs and a reduction of interstitial iron concentration from 1.32 × 10¹³ at/cm³ to 8.4 × 10¹⁰ at/cm³ are demonstrated in this paper. Copyright © 2013 John Wiley & Sons, Ltd.     

Bit-serial window partitioning algorithm for stack filtering

The authors introduce a new bit-serial algorithm for stack filtering, designated as the bit-serial window partitioning algorithm. It is shown that the proposed algorithm can achieve very important savings over the conventional bit-serial binary-tree search algorithm, in terms of the computational speed. This improved efficiency is obtained by evaluating the Boolean function at thresholds corresponding to the sample values within the filter window, and by taking advantage of the ordering information associated with the threshold sequences     

Dynamic scattering in binary compensate cholesteric mixture with pleochroic dye added

The paper reports measurements of optical transmittance and of I–V characteristic performed simultaneously on the same host mixture ChCl + LCh 74:26% molar in which was introduced another azocumilphenol derivative from paraphenetidine (Dpf). The optical and electrical measurements were interpreted by correlating them with the microstructural aspects recorded by a polarizing microscope in the same conditions of field and temperature.     

Design and tuning of a 40-MeV electron linear accelerator

The 40-MeV electron linear accelerator RELUS-6 with a 100-mA pulse current has been designed. The standing wave accelerator with a biperiodic accelerating structure is composed of four sections and is powered from two 6-MW pulse klystrons. The operating frequency is 2856 MHz. The total length of the accelerating structure is 2.73 m. Calculations have been performed with the aim of selecting the lengths of the first three cells in the first accelerating section and the values of the accelerating field in them, so that the width of the energy spectrum at the end of the accelerator is 2%. The geometry of the accelerating structure and the power input cells has been designed. Four accelerating structures have been manufactured based on the simulation results. The structures have been tuned to the operating frequency, the predetermined accelerating field distribution, and a fixed coupling between the feed waveguide and the accelerating section.