Simulation of dynamic phosphor space charge in alternating-current thin-film electroluminescent (ACTFEL) devices is performed using SPICE equivalent circuit models. Two SPICE equivalent circuits are developed; one for the case of space charge creation via impact ionization and another for field emission. Both SPICE equivalent circuits are based on modeling the space charge distribution as a sin...

Space charge lenses for ion beam focussing are in theory, especially for singly charged heavy ion beams at low velocities, superior to other lens systems [1]. On the other hand previous experiments [2] have shown, in contrary to the theoretical forecast, a small degree of lens filling and serious emittance growth. Newer experiments [3] demonstrated a much better degree of lens filling and subst...

Polymer light-emitting transistor is realized by vertically stacking a top-emitting polymer light-emitting diode on a polymer space-charge-limited transistor. The transistor modulates the current flow of the light-emitting diode by the metal-grid base voltage. The active semiconductor of the transistor is poly 3-hexylthiophene . Yellow poly para-phenylene vinylene derivative is used as the yell...

In order to contribute to the development of high power proton accelerators in the MW range, to prepare the way for an ISIS upgrade and to contribute to the UK design effort on neutrino factories, a front end test stand (FETS) is being constructed at the Rutherford Appleton Laboratory (RAL) in the UK [1]. The aim of the FETS is to demonstrate the production of a 60 mA, 2 ms, 50 pps chopped beam...

Space-charge-induced emittance growth and halo generation could lead to unacceptably high beam loss in high intensity rings, such as the SNS [1]. In such accelerators, uncontrolled losses to the walls as small as one part in 10 would lead to activation, making maintenance difficult. For this reason it is essential to understand the effects of space charge on beam dynamics, and halo generation i...

Ž . Plume clouds resulting from wildland fires pyrocumulus sometimes produce lightning discharges to ground. These discharges were found to carry positive charge to ground exclusively in several cases. Emission of space charge was observed from woody materials burned in the presence of an external electric field. Measurements done in a large wind tunnel for this study confirm and extend measure...

Based on the Vlasov-Maxwell equations describing the self-consistent nonlinear beam dynamics and collective processes, the evolution of an intense sheet beam propagating through a periodic focusing field has been studied. It has been shown that in the case of a beam with uniform phase space density the Vlasov-Maxwell equations can be replaced exactly by the hydrodynamic equations with a triple ...

Contacts of two phases, which allow for synergistic dissociative storage of a component in two space charge zones ("job-sharing storage"), are considered from the viewpoint of point defect thermodynamics. The respective relations between charge and component activity (chemical potential of the component) are derived, or - for more complex cases - the recipes for their derivation are given. Thes...

The model of space-charge formation in photorefractive polymers due to Schildkraut and Buettner has been modified to include thermally accessible deep traps as well as shallow traps. The dynamic equations have been solved semiempirically using independent measurements of photoconductive properties to predict photorefractive dynamics. Dependencies of the dynamics on charge generation, mobility, ...