We experimentally investigate how disorder comes about in parametrically excited waves on a fluid surface (Faraday waves). We find that the transition from an ordered pattern to disorder corresponding to "defect-mediated turbulence" is mediated by a spatially incoherent oscillatory phase. This phase consists of highly damped waves that propagate through the effectively elastic lattice defined b...

Parametrically excited surface waves (Faraday waves) are studied near the threshold for breaking. The breaking state ejects droplets from wave peaks when the applied forcing exceeds an acceleration threshold. The rate of breaking events approaches zero gradually with decreasing acceleration. Two properties of these ejections were studied around the ejection threshold. Analysis of the ejection r...

We consider electron heating in the sheath regions of capacitive discharges excited by a combination of two frequencies, one much higher than the other. There is a common supposition that in such discharges the higher frequency is the dominant source of electron heating. In this letter, we discuss closed analytic expressions quantifying the Ohmic and collisionless electron heating in a dual fre...

Transport properties of one-dimensional Kronig-Penney models with binary correlated disorder are analyzed using an approach based on classical Hamiltonian maps. In this method, extended states correspond to bound trajectories in the phase space of a parametrically excited linear oscillator, while the on site-potential of the original model is transformed to an external force. We show that in th...

We analyze two-color spatially localized nonlinear modes formed by parametrically coupled fundamental and second-harmonic fields excited at quadratic (or chi(2)) nonlinear interfaces embedded in a linear layered structure--a quadratic nonlinear photonic crystal. For a periodic lattice of nonlinear interfaces, we derive an effective discrete model for the amplitudes of the fundamental and second...

The vibrational characteristics of a cantilever beam are well known to strongly depend on the fluid in which the beam is immersed. In this paper, we present a detailed theoretical analysis of the frequency response of a cantilever beam, that is immersed in a viscous fluid and excited by an arbitrary driving force. Due to its practical importance in application to the atomic force microscope ~AF...

The coupled-bunch beam breakup (bbu) problem in a periodic linac excited by the resonance wake is well understood [1–3]. However, there are no systematic studies for the corresponding problem excited by the resistive wall impedance. This study of the resistive wall bbu problem is necessitated by the recently proposed PERL project [4]. For PERL, the light source consists of twelve undulators, ea...

This paper describes the synthesis of digitally excited pencil/flat top dual beams simultaneously in a linear antenna array constructed of isotropic elements. The objective is to generate a pencil/flat top beam pair using the excitations generated by the evolutionary algorithms. Both the beams share common variable discrete amplitude excitations and differ in variable discrete phase excitations...

Introduction The lithium beam diagnostic provides a powerful edge plasma diagnostic. It enables the determination of electron density profiles in the scrape-of-layer and pedestal region with high spatial and temporal resolution (∆t ≈ 50ms, ∆x ≈ 1cm). A fast neutral lithium beam (beam energy at JET: 55 keV) is injected into the plasma and the line radiation emitted by the collisionally excited l...

We will consider the cavity shown in Fig. (2.1) which has rotational symmetry about the z axis and is excited by the beam current, IB, passing through the gap. For the time being, we will consider only one mode of excitation for the cavity; namely, the mode where the magnetic field ~ B is azimuthal around the beam direction as shown. The current IL flows in the outer cavity wall in the directio...