A vectorial modal method is presented based on transverse magnetic and electric mode expansion, which significantly simplifies the evaluation of operator matrix. The method, features a true open boundary condition, introduced for an orthogonal curvilinear coordinate system with specific examples circular elliptical geometries presented. We validate by considering challenging problems, such as c...

UNLABELLED An object-oriented software system is described for estimating internal emitter absorbed doses using a set of computer modules operating within a personal computer environment. The system is called the Radionuclide Treatment Planning and Absorbed Dose Estimation System (RTDS). It is intended for radioimmunotherapy applications, although other forms of internal emitter therapy may als...

We report InP/In0.53Ga0.47As/InP double heterojunction bipolar transistors (DHBTs) demonstrating simultaneous 460 GHz f and 850 GHz fmax. The devices were fabricated using a triple mesa process with dry-etched, refractory metals for emitter contact formation. The devices incorporate a 35 nm thick InP emitter which enables a wet etch emitter process demonstrating 220 nm wide emitter-base juncti...

pet (positron emission tomography) is a powerful imaging technique that can provide quantitative information on the distribution of positron emitter labeled radiopharmaceuticals (pet radiopharmaceuticals) in the body. positrons (ß+) are positively charged beta particles. they are emitted when the atom is proton rich. a positron has only a transient existence. after losing all of its kinetic ene...

Carbon nanotube has good electrical properties and a high aspect ratio, which enable it to obtain a high current at a low voltage due to its high field. Due to the life and uniformity of their emission tips, carbon nanotube field emitters are hard to commercialize. A field emitter with a three-dimensional (3D) structure was fabricated in this study to overcome such problems. In the 3D-structure...

In this article, we are discussing the Gauss’s law used to determine the width emitter extension region of the solar cell operating in open circuit condition. Taking into account the grain size (g), the grain boundary recombination velocity (Sgb) and the emitter doping density (Nemitter), the Gauss’s Law helped us to calculate the width emitter extension region of the solar cell operating in op...

Electrospray thrusters utilize a strong electric field to extract and accelerate charged particles contained at a needle tip in a liquid state [1]. Electrospray thrusters are one of the few types of electric propulsion systems that can offer high specific impulses (i.e. >1000 seconds) whilst still being scalable down to fit within a 1U CubeSat form structure. These small electrospray thrusters,...

Femtosecond ultrabright cathodes with spatially structured emission are a critical technology for applications such as free-electron lasers, tabletop coherent x-ray sources, and ultrafast imaging. In this work, the optimization of the total electron yield of ultrafast photon-triggered field emission cathodes composed of arrays of nanosharp, high-aspect-ratio, single-crystal silicon pillars is e...

SiGe heterojunction bipolar transistors (HBTs) have been fabricated using selective epitaxy for the Si collector, followed in the same growth step by nonselective epitaxy for the p SiGe base and n-Si emitter cap. DC electrical characteristics are compared with cross-section TEM images to identify the mechanisms and origins of leakage currents associated with the epitaxy in two different types o...