This paper presents a hybrid numerical method for the electromagnetic field coupling into apertures residing on the surface of rectangular cavities. The cavity may enclose wires and cables that are typically modeled via transmission line approaches. Coupling into the cavity is analyzed via the moment method along with the cavity Green’s function to find the aperture fields whereas Pocklington’s...

A common coil design concept for 2-in-1 superconducting accelerator magnets is presented. It practically eliminates the major problems in the ends of high field magnets built with either high temperature superconductors (HTS) or conventional superconductors. Racetrack coils, consisting of rectangular blocks built with either superconducting tapes or cables, are common to both apertures with eac...

Transmission properties through sharp rectangular waveguide bends are investigated to determine the cut-off bending angles of the wave propagation. We show that a simple metallic diaphragm at the bending corner with properly devised sub-wavelength defect apertures of C-slits would be readily to turn on the transmissions with scarce reflections of the propagating modes, while preserving the inte...

Solute transport in fractured rocks is of major interest in many applications: geothermal energy production, petroleum industry, ground water management. This work focuses on a dispersion experiment performed with a transparent replica of a real fracture. The local aperture map was extracted using the well-known Beer-Lambert law, which shows a very heterogeneous medium. The hydrodynamic apertur...

The performance of future linear colliders are limited by the effect of short-range collimator wakefields on the beam. The beam quality is sensitive to the positioning of collimators at the end of the linac. The determination of collimator wakefields has been difficult, largely because of the scarcity of measurement data, and of the limitation of applicability of analytical results to realistic...

It is shown that for micrometre-sized beams the X-ray diffraction from slits is a source of strong parasitic background, even for slits of high quality. In order to illustrate this effect, the coherent diffraction from rectangular slits has been studied in detail. A large number of interference fringes with strong visibility have been observed using a single set of slits made of polished cylind...

In light-optical microscopes, numerical apertures (apertures in the back focal plane of the objective lens) are an integral part. Often, these apertures can be adjusted continuously, e.g., in single lens reflex (SLR) cameras. In electron microscopy however, and despite much larger magnification ranges, there is only a limited selection of fixed apertures. This is due a) to the pm wave length of...

In this paper, we present multiple techniques for phase-based narrowband backscatter tag localization in three-dimensional space with planar antenna arrays or synthetic apertures. Beamformer and MUSIC localization algorithms, known from near-field source localization and direction-of-arrival estimation, are applied to the 3D backscatter scenario and their performance in terms of localization ac...

Efficient homogeneous illumination of rectangular or circular areas with LEDs is a promising application for doublesided microlens arrays. Such illumination schemes employ a primary optics which can be realized with a concentrator or a collimation lens and a secondary optics with one or more double-sided microlens arrays and a collection optics for superposing the light from the individual arra...

We propose a new model to account for the main structural characteristics of rock fracture networks (RFNs). The model is based on a generalization of the random neighborhood graphs to consider fractures embedded into rectangular spaces. We study a series of 29 real-world RFNs and find the best fit with the random rectangular neighborhood graphs (RRNGs) proposed here. We show that this model cap...