Abstract: A cold emitter x-ray tube is provided comprised of a cathode which is a carbon nanotube or nanostructured carbon film which serves as the electron emission source in an x-ray tube, and is positioned on a suitable substrate. The nanostructured carbon film is selected from a group consisting of nanocyrstalline graphite, carbon nanotubes, diamond, diamond like carbon, or a composite of two or more of members of the group. An extraction/suppression grid may be utilized. A metal anode which functions as the x-ray generating target is positioned within the x-ray tube. A high voltage source with negative contact is connected to the emitter and the positive contact connected to the anode target. This single source of high potential serves to provide the electric field, between the emitter and anode, for extraction of electrons from the emitter and to accelerate the electrons to the target for generation of x-rays. X-rays pass through a beryllium window that is an integral part of the vacuum envelope.
Type:
Application
Filed:
August 20, 2002
Publication date:
January 2, 2003
Applicant:
Oxford Instruments, Inc.
Inventors:
Robert J. Espinosa, Bradley W. Boyer, Scott Snyder, Majorie L. Munson, Ken G. Gorman
Abstract: A portable x-ray fluorescence spectrometer apparatus comprising a housing; a high voltage energized x-ray source operably secured within the housing; and an unheated electron cathode, operably linked to the high voltage energized x-ray source, thereby eliminating the need for a cathodic electron power supply for spectrometric analysis. Another embodiment comprises a portable x-ray fluorescence spectrometer having a housing, an integrated x-ray tube, a high voltage power supply operably linked to the integrated x-ray tube, and a mechanism for controlling the x-ray emissions of the x-ray tube and power supply including an electron suppression grid operably positioned between a filament cathode and a target anode of the x-ray tube.
Abstract: A method for producing a multifilamentary superconductor containing niobium-tin (Nb.sub.3 Sn). A fully bonded niobium/copper composite billet is formed having a plurality of longitudinally extending channels which are symmetrically distributed with reference to transverse cross-sections of the billet, each channel being filled with an inert removable filler material. The inert filler material is removed to open the longitudinally extending channels in the billet. Tin or a tin alloy is inserted into the channels, and the niobium/copper composite billet with the inserted tin or tin alloy is cold drawn to the desired final dimensions. The drawn composite is then heated to effect in situ formation of the niobium-tin.
Type:
Grant
Filed:
May 27, 1994
Date of Patent:
July 9, 1996
Assignee:
Oxford Instruments Inc.
Inventors:
William G. Marancik, Seungok Hong, Rouyi Zhou