USA As Represented by Secretary of the Navy

The Titan Corporation

John D Sethian

Matthew C Myers

Frank Hegeler

Mathew Wolford

Moshe Friedman

Douglas M Weidenheimer

Ronald L Holtz

David M Giorgi

Kathryn J Wahl

Derek Horton

Matthew F Wolford

Alexis C Lewis

An improved process and for removing NOfrom exhaust gases produced by combustion-based energy sources. Catalyst-free exhaust gas is directed into one or more ducts. The gas is cooled and then passes through the duct, wherein the gas flow rate and the electron beam pulse rate are configured to cause each successive volume of gas that flows past the window to be subjected to only a single electron beam pulse in the reaction chamber. A single short, intense electron beam is fired into the exhaust through a window in the reaction chamber as the exhaust flows past the window, with some of the electrons being reflected back into the gas by a reflective plate situated opposite the window. The deposited electron energy causes NOfrom the exhaust to be converted into Nand Owhich are output into the atmosphere with the thus-scrubbed exhaust.

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A method for desensitizing an aluminum alloy is presented. A desired location on the surface of an aluminum alloy sample is exposed to a controlled pulsed electron beam. The pulsed electron beam heats a shallow layer of the metal alloy having a desired depth at the desired location on the surface of the sample to a temperature between a solvus temperature and an annealing temperature of the metal alloy to controllably reduce a degree of sensitization of the metal alloy sample at the desired location, an extent of a reduction in the degree of sensitization being controllable by varying at least one of a voltage, a current density, a pulse duration, a pulse frequency and a number of pulses of the electron beam.

Desensitization of aluminum alloys using pulsed electron beams

A process and apparatus for removing NOfrom exhaust gases produced by combustion-based energy sources. An array of high voltage pulsed electron beams are repetitively generated and transported through a thin foil into the exhaust gas containing NO. The electron beam deposits its energy into the gas and produces reactive radicals N, N, e, Nfrom the NOin the gas. These radicals recombine through chemical reactions to produce benign by-products nitrogen Nand oxygen Owhich are output into the atmosphere.

A high power diode includes a cathode for emitting a primary electron discharge, an anode, and a porous dielectric layer, e.g. a honeycomb ceramic, positioned between the cathode and the anode for receiving the primary electron discharge and emitting a secondary electron discharge. The diode can operate at voltages 50 kV and higher while generating an electron beam with a uniform current density in the range from 1 A/cmto &#x3e;10 kA/cmthroughout the area of the cathode. It is capable of repetitively pulsed operation at a few Hz with pulse duration from a few nanoseconds to more than a microseconds, while the total number of pulses can be &#x3e;10pulses. The diode generates minimal out-gassing or debris, i.e. with minimal ablation, providing a greater diode lifetime, and can operate in a high vacuum environment of 10Torr. The high power diode is useful in many applications requiring a high current electron beam. Exemplary applications include x-ray photography of large samples, polymerization processes, sterilization of biological and chemical agents, irradiation of food, and as a pump for lasers, e.g. excimer lasers such as krypton fluorine (KrF) lasers.

High power diode utilizing secondary emission

A laser-activated semiconductor switching device includes a semiconductor assembly including a multi-layer semiconductor structure having a first principal surface, and a laser assembly. The laser assembly includes at least one laser device and is directly connected to said first principal surface. The first principal surface includes a window area from which a metallization layer and an emitter layer of the semiconductor assembly are masked, such that laser light emitted from the laser assembly impinges through the window area directly onto a base layer of said semiconductor assembly to initiate current conduction by said switching device.

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Burke, VA, United States of America

John D Sethian