In this paper‎, ‎the static bending‎, ‎free vibration‎, ‎and dynamic response of functionally graded‎ ‎piezoelectric beams have been carried out by finite element method‎‎under different sets of mechanical‎, ‎thermal‎, ‎and electrical‎ ‎loadings‎. ‎The beam with functionally graded piezoelectric material‎ ‎(FGPM) is assumed to be graded across the thickness with a simple‎ ‎power law distributio...

The following paper describes and discusses the suitability of the particle swarm optimization (PSO), of the simulated annealing algorithm (SA) and of the genetic algorithm (GA) for the employment with blind adaptation of the directional characteristic of array antennas. By means of extensive simulations, it was confirmed that the suggested PSO and SA and the improved GA are able to follow dyna...

Tunnel ionizing neutral gas with the self-field of a charged particle beam is explored as a possible way of creating plasma sources for a plasma wakefield accelerator [Bruhwiler et al., Phys. Plasmas (to be published)]. The optimal gas density for maximizing the plasma wakefield without preionized plasma is studied using the PIC simulation code OSIRIS [R. Hemker et al., in Proceeding of the Fif...

The role that small particle accelerators play in the field of applications to Cultural Heritage (for material analysis and dating) is critically discussed also in comparison to other techniques, pointing out pros and cons. As to material analysis, some peculiarities of ion beam techniques may be now less unique than they were perhaps ten years ago, but these techniques can still reach unrivall...

The stability of non-linear Integrable Optics Test Accelerator (IOTA) model developed in [1] was tested. The area of the stable region in transverse coordinates and the maximum attainable tune spread were found as a function of non-linear lens strength. Particle loss as a function of turn number was analyzed to determine whether a dynamic aperture limitation present in the system. The system wa...

SLAC’s Advanced Computations Department (ACD) has developed the first parallel Finite Element 3D Particle-In-Cell (PIC) code, Pic3P, for simulations of RF guns and other spacecharge dominated beam-cavity interactions. Pic3P solves the complete set of Maxwell-Lorentz equations and thus includes space charge, retardation and wakefield effects from first principles. Pic3P uses higher-order Finite ...

Many measurements on the beam-beam limit in SPEAR have been performed over the past eight years since colliding beam operation began. The goal for these measurements was to find the proper parameterization of the beambeam effect. Earlier measurements I,21 in SPEAR, however, were limited in their validity by two circumstances. First, until 1978 we had no control over the so-called flip-flop phen...

Our main objective in this article is to achieve minimum side lobe levels for a specific first null beam-width and also a minimum size of the circumference by an optimization-based design method for non-uniform, planar, and circular antenna arrays. Our approach is based on a new variant of Particle swarm Optimization technique. This new technique is a hybrid of Local Neighborhood based PSO with...

The Hα line profile in moustaches is characterized by enhanced wings and a deep central absorption. We explore the possibility that such a profile may be due to the effect of energetic particles bombarding the atmosphere. Computations show that the characteristics of moustache line profiles can be qualitatively reproduced in two extreme cases, either injection from the corona of high energy par...