In this report we study the dynamics of passive quenching in a single-photon avalanche diode. Our discussion is based on microscopic description electron-hole coupled to equivalent circuit device, consisting quench resistor and junction capacitance. Analytic expressions for resulting signal shape are derived from model simple electric field configurations, efficient numerical prescriptions give...

The optical properties of InGaN/GaN laser diode based on quaternary alloys stopper and superlattice layers are numerically studied using ISE TCAD (Integrated System Engineering) simulation program. Improvements in laser optical performance have been achieved using quaternary alloy as superlattice layers in InGaN/GaN laser diodes. Lower threshold current of 18 mA and higher output power and slop...

Halo formation and control in space-charge-dominated electron and ion beams are investigated in parameter regimes relevant to the development of high-power microwave (HPM) sources and highintensity electron and ion linear accelerators. In particular, a mechanism for electron beam halo formation is identified in high-power periodic permanent magnet (PPM) focusing klystron amplifiers. It is found...

background: understanding of the incident electron energy and angular distributions from clinical electron accelerators (linacs) is important for dosimetry and treatment planning. the most important goals of this study were to evaluate the energy fluence and angular distributions of electron beams from a neptun 10pc linac using the monte carlo (mc) code. materials and methods: the linac electro...

The characteristics of field electron and ion emission change when the space charge formed by emitted is sufficient to suppress extracting electric field. This phenomenon well described for planar emitting diodes one dimensional (1D) theory. Here we generalize any 3D geometry deriving scaling laws describing suppression in weak regime. We propose a novel corrected equivalent diode model, which ...

A new switching mechanism in a two-terminal semiconductor heterolayer structure Is proposed which capitalizes on non-linear electron temperature effects in adjacent heterolayers. The estimated switching speed of an optimized heterostructure hot electron diode should be extremely fast, perhaps as fast as 200 femtoseconds. Data are presented on prototype devices which show the expected negative d...

A tapered AlGaN electron blocking layer with step-graded aluminum composition is analyzed in nitride-based blue light-emitting diode (LED) numerically and experimentally. The energy band diagrams, electrostatic fields, carrier concentration, electron current density profiles, and hole transmitting probability are investigated. The simulation results demonstrated that such tapered structure can ...

The existing model of a "co l l is ionless" alkali plasma diode is extended including the case of two incandescent plane electrodes emitting electrons as well as ions with a half-Maxwellian velocity distribution. The potential distributions within the diode space derived from this theory are examined in detail. Physically necessary conditions reduce the well-known ambiguity of solutions to a si...

Dosimetric comparisons of radiation fields produced by Varian's newest linear accelerator, the TrueBeam, with those produced by older Varian accelerators are of interest from both practical and research standpoints. While photon fields have been compared in the literature, similar comparisons of electron fields have not yet been reported. In this work, electron fields produced by the TrueBeam a...