The strawman PASS design calls for the use of a CONUS beam for transmission between the supplier and the satellite and for fixed beams for transmission between the basic personal terminal (BPT) and the satellite. The satellite uses a 3m main reflector for transmission at 20 GHz and a 2m main reflector for reception at 30 GHz. The beamwidth of the reflector is 0.35°. To cover CONUS 142 fixed bea...

With the start of the machine studies to characterize the behaviour of the LHC beam in the SPS in 1999, it became evident that electron multipacting was occurring in the SPS vacuum chambers in the presence of this beam. Multipacting induces dramatic pressure increases preventing stable operation, it limits the performance of beam instrumentation and high voltage electrostatic devices (e.g. elec...

In this paper we investigate the self-focusing of a Gaussian beam in a saturable nonlinear medium. We show that the dynamics of the incident Gaussian beam become progressively more complicated as the ratio of the Gaussian spot size to that of the ground-state solution is increased for a fixed energy flux. As this ratio is increased (or decreased) from unity, recurrence of the field is observed ...

A vector hydrophone is composed of two or three spatially collocated but orthogonally oriented velocity hydrophones plus an optional collocated pressure hydrophone. A vector hydrophone may form azimuth-elevation beams that are invariant with respect to the sources’ frequencies, bandwidths and radial location (in near field as opposed to the far field). This paper characterizes the spatial match...

Based on a combined analytical and numerical modelling, a high-quality probe-forming system is proposed and developed. The Matrizant method is applied to minimize the beam spot size for a fixed beam current. For quadrupoles consisting of four metallic rods, the electric field inside of the quadruplet is computed using an accurate version of the boundary element method. The influence of the rod ...

A novel approach in quantifying code orthogonality factor for UTRA-FDD systems is extended in this paper to include the impact of down-link beamforming. The effects of fixed beam forming on code orthogonality is analysed through the aid of real channel data taken from urban cellular environments. The results show a significant overall improvement in code orthogonality with beam forming, especia...

background: the assessment of rbe quantity in the treatment of cancer tumors with proton beams in treatment planning systems (tps) is of high significance. given the significance of the issue and the studies conducted in the literature, this quantity is fixed and is taken as equal to 1.1. objective: the main objective of this study was to assess rbe quantity of proton beams and their variations...

An opt ica l imaging sys tem provides automatic co-registration of a plurality of multi spectral images of an object which are generated by a plurality of video cameras or other optical detectors. The imaging system includes a modular assembly of beam splitters, lens tubes, camera lenses and wavelength selective filters which facilitate easy reconfiguration and adjustment of the system for vari...