A new scheme for the two-dimensional cooling of ion beams in storage rings is suggested in which ions interact with a counterpropagating broad-band laser beam. The interaction region in the direction of the ion movement is much less then the wavelength of the ion betatron oscillations. The laser beam in the orbit plane has sharp flat edge directed to the ion beam and the width of the laser beam...

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,...

A smart antenna for mobile applications incorporating an array of ± 45 polarised stacked patch elements 4 columns wide excited by a multi-beamforming and beam shaping network is described. Four narrow overlapping beams, one wide “broadcast channel” beam and right and left shaped beams can be provided. The later shaped beams are to provide high capacity coverage in a specific narrow angular sect...

the basic strategy of reduce the ductility demand and related concentrated tensions at moment resistance connections is reduce the section of the beam at connected region to column. by this method plastic hinge done at the reduced cross section and this local reduction decreases the demand of the components of connection. on this basis, in present study a new beam-to-column moment connection wi...

The CESR Luminosity Upgrade Plan consists of several consecutive steps, or phases [1]. At the present time, this program is in Phase II. The next step, Phase III, would yield a luminosity of 1x1033cm-2sec-1 with 45 bunches in each beam for a total current of 1 A. This plan utilizes four superconducting single-cell cavities with an accelerating gradient of 6 MV/m, which corresponds to a peak acc...

Vibrational spectroscopy has been widely applied in different fields due to its label-free chemical-sensing capability. Coherent anti-Stokes Raman scattering (CARS) provides stronger signal and faster acquisition than spontaneous Raman scattering, making it especially suitable for molecular imaging. Coherently-controlled single-beam CARS simplifies the conventional multi-beam setup, but the vib...

studying gaussian beam is a method to investigate laser beam propagation and abcd matrix is a fast and simple method to simulate gaussian beam propagation in different mediums. of the abcd matrices studied so far, reflection and refraction matrices at various surfaces have attracted a lot of researches. however in previous work the incident beam and the principle axis of surface are in parallel...

This paper presents analytical fan-beam and cone-beam reconstruction algorithms that compensate for uniform attenuation in single photon emission computed tomography. First, a fan-beam algorithm is developed by obtaining a relationship between the two-dimensional (2D) Fourier transform of parallel-beam projections and fan-beam projections. Using this relationship, 2D Fourier transforms of equiv...

Gradient-index dielectric lenses are generated based on the coordinate transformation by compressing the homogeneous air spaces quasi-conformally towards and outwards the primary source. The three-dimensional modeling is then performed through revolving the prescribed transformational media 180 degrees around the focal point to reach the architecture of barrel-vaults. It is found that all these...

Multimodal multiplex spectroscopy (MMS) has been demonstrated to increase the optical throughput of a spectrometer as opposed to that of conventional optical spectrometers [5] and has been implemented using three-dimensional photonic crystals [5] and spherical-beam volume holograms recorded in the transmission geometry [6-7, 9] as spectral diversity filters. While such efforts have resulted in ...