The reflectarray’s elements arrangement for generating an arbitrary phase distribution in the antenna aperture and thus a wide beamwidth of the far field pattern is presented. The desired phase delay of reflectarray elements, which duplicated the same radiating aperture as backscatters, is determined on the construction of the curvature of a shaped backscatter surface with the help of Snell's l...

The use of arrays and the possibility of electronic beam steering, focusing and side lobe suppression allows a better defect classification and reconstruction of defective areas in work pieces, components and industrial plants. Because of synthesizing a large sector by a narrm'i ultrasonic beam, the advantage of a narrow beam for oood signal/noise ratio is combined with the advantage of a broad...

Cone beam X-ray luminescence tomography can realize fast X-ray luminescence tomography imaging with relatively low scanning time compared with narrow beam X-ray luminescence tomography. However, cone beam X-ray luminescence tomography suffers from an ill-posed reconstruction problem. First, the feasibility of experiments with different penetration and multispectra in small animal has been teste...

Introduction: In clinical electron beams, most of bremsstrahlung radiation is produced by various linac head structures. This bremsstrahlung radiation dose is influenced by the geometry and construction of every component of the linac treatment head structures. Thus, it can be expected that the amount of the contaminated photon dose due to bremsstrahlung radiation varies among different linacs,...

Remote sensing applications often require high energy laser-like beams with narrow bandwidth and low divergence at wavelengths that cannot be reached directly with ordinary laser materials. The common way of generating such wavelengths is through optical parametric oscillators (OPOs), sumor difference frequency generators, or a combination of these. For the new beam to be generated with high co...

Abstract A simple method is proposed to model the open cracked beam structures. In this method, crack is modeled as a beam element. Hence cracked beam can be assumed to be a beam with stepped cross sections, and problem of determining natural frequency and mode shape of cracked beam, can be solved as determining these characteristics for a beam with different length and cross section. With this...

In order to reduce the emittance and increase the transported beam current from the ISIS Penning-type H(-) ion source, improvements to the extraction system are required. This ion source is currently being commissioned on the front end test stand at the Rutherford Appleton Laboratory, which demands higher extraction energies, higher beam currents, and smaller emittances. To facilitate this, the...

The nature of the scattering pattern for silicon 004 wafer is described. At incidence angles (ω) set close to the expected diffraction condition of ω = θh`k`l` αhkl,h`k`l` (hkl are the planes parallel to the wafer surface and αhkl,h`k`l` is the interfacial angle between hkl and another set of diffracting planes h’k’l’), an anomalous kind of scattering has been observed. There is a broad weak fe...

The FIB Instrument The basic functions of the FIB, namely, imaging and sputtering with an ion beam, require a highly focused beam. A consistent tenet of any focused beam is that the smaller the effective source size, the more current that can be focused to a point. Unlike the broad ion beams generated from plasma sources, high-resolution ion beams are defined by the use of a field ionization so...