USA As Represented by Secretary of the Navy

Other

Michael S McDonald

Michael W Nurnberger

Kevin Jensen

Marcel Georgin

A cathode emitter assembly includes a cathode tube having a gas feed portion and a plasma outflow portion; an outer annular cathode insert in the plasma outflow portion of the cathode tube; an inner cathode insert in the plasma outflow section of the cathode tube; and an annular plasma emission portion defined between an inner surface of the outer annular cathode insert and an outer surface of the inner cathode insert.

Annular hollow cathode

Methods and apparatuses for emitting electrons from a hollow cathode are provided. The cathode includes a plasma holding region configured to hold a plasma, a gas supply source configured to supply gas to the plasma holding region, and an orifice plate disposed on a periphery of the plasma holding region. The orifice plate comprises a plurality of openings constructed to receive electrons from the plasma. The plurality of openings decouple gas conductance and electrical conductance across the orifice plate. The diameters of the plurality of openings are within a range of 20%-60%, inclusive, of a diameter of a circular opening with an area equal to a sum of the areas of the plurality of openings.

Methods and apparatuses for emitting electrons from a hollow cathode

A compound field emitter (CFE) includes a first surface possessing a field enhancement factor &#x3e;1, and a second surface possessing one or both of a field enhancement factor &#x3e;1, or a low work function, wherein the second surface is coated, formed or applied upon the first surface. The second surface has a characteristic size at least 3 times smaller than the first surface, and the outer surface includes a coating of calcium aluminate 12CaO-7Al2O3.

Thermally enhanced compound field emitter

An apparatus includes a radio frequency ('RF') translational joint. The RF translational joint includes a first coaxial line. The RF translational joint includes a first constant impedance coaxial transition connected to the first initial coaxial line. The RF translational joint includes a coax-to-stripline transition. The RF translational joint includes a stripline section connected to the first constant impedance coaxial transition via the coax-to-stripline transition. The RF translational joint includes a stripline-to-coax transition. The RF translational joint includes a second constant impedance coaxial transition connected to the stripline section via the stripline-to-coax transition. The RF translation joint includes a second coaxial line connected to the second constant impedance coaxial transition.

Method and/or apparatus for frictionless wideband high-power radio-frequency power transmission across a freely moving interface

Embodiments relate to a hallow cathode with integral layers of radiation shielding. The hollow cathode includes an inner cathode tube that forms a gas feed to direct gas toward a downstream end, where the directed gas forms plasma. A heater element is positioned at the downstream end of the inner cathode tube, the heater element to heat the plasma. The hollow cathode further includes an outer cathode tube with a keeper electrode to sustain a bias voltage across a gap at a downstream end of the outer cathode tube for igniting the plasma. The integral layers of radiation shielding are connected by offset radial supports and are incorporated as a single element with either the inner or outer cathode tube, where the integral layers are nested with torturous conductive paths to reduce radiation and conduction losses from the downstream end of the inner cathode tube.

Thermally isolated thermionic hollow cathodes

An evacuation assistance locator, which includes a processor communicative with a memory device contained with a housing, is detachably mounted to a fixed structure, such as an office building, for receiving location information from non-ambulatory individuals to assist emergency personnel in quickly finding the non-ambulatory individuals location in the event of an emergency. The housing also includes a display screen and an input keypad so that the non-ambulatory individual can input their location and departure time information and so that only authorized emergency personnel can retrieve the location information by using a secret access code. A plurality of evacuation assistance locations can be linked to a central office for access by the appropriate personnel.

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Springfield, VA, United States of America

Michael S McDonald