Abstract:
PROBLEM TO BE SOLVED: To provide a radiation generation apparatus which is made compact, and improves a dielectric withstanding voltage between an envelope and a radiation generation tube and reduces an attenuation amount of radiation, and a radiation photography apparatus using the same.SOLUTION: The radiation generation apparatus includes an envelope 12 which has a first window 27 transmitting radiation; a radiation generation tube 14 which is housed in the envelope 12 and has a second window 19 transmitting radiation at a position opposed to the first window 27; and an insulating fluid 13 charged between an inner wall of the envelope 12 and the radiation generation tube 14. A plurality of insulating plate materials are arranged side by side between the first window 27 and its peripheral edge part, and the second window 19 and its peripheral edge part while leaving gaps. The gaps between the insulating plate materials are such that dielectric withstanding voltage between the first window 27 and second window 19 is larger than that when an insulating plate material having a thickness equal to the total of thicknesses of the respective insulating plate materials is arranged instead of the plurality of insulating plate materials.
Abstract:
An X-ray source for producing soft X-rays, the X-ray source comprising: a cathode having an electron-emitting structure supported by a support structure, the electron-emitting structure being at least partially transparent to X-rays within a region bounded by the support structure;an anode having an X-ray emitting surface parallel to the electron-emitting structure of the cathode; and an electrically insulating spacer arranged between the anode and the cathode;wherein the electron-emitting structure of the cathode and the X-ray emitting surface of the anode are arranged such that, in use, the electron-emitting structure is operable to bombard the anode with electrons, causing X-rays to be emitted from the X-ray emitting surface and to pass through the cathode; and wherein the insulating spacer is arranged between the anode and the support structure of the cathode and projects beyond the support structure, across part of the anode,into the said region.
Abstract:
An apparatus and method comprising a cathode structure which can be a cylindrical filament coiled in a helix or which can be constructed of a ribbon or other suitable shape. The cathode structure can be heated by passage of an electrical current, or by other means such as bombardment with energetic electrons. Selected portions of the surface of the cathode structure have an altered property with respect to the non-selected portions of the surface. In one embodiment, the altered property is a curvature. In another embodiment, the altered property is a work function. By altering the property of the selected portions of the surface, the electron beam intensity is increased, and the width is decreased.
Abstract:
The invention relates to an X-ray tube (1) comprising a vacuum container (3), an anode (4) and a cathode (5) disposed within said container (3), wherein the cathode (5) is an extended area emitter. It is an object of the invention to provide rapid controllability of the extended area emitter without compromising the emitter's mechanical stability. To achieve this object the X-ray tube comprises a radiation module (2, 8) adapted to direct pulsed radiation (9) onto the emitter to heat the emitter surface (6) to cause thermionic emission of electrons (12).
Abstract:
Methods and apparatus for independent control of electron emission current and x-ray energy in x-ray tubes are provided. The independent control can be accomplished by adjusting the distance between the cathode and anode. The independent control can also be accomplished by adjusting the temperature of the cathode. The independent control can also be accomplished by optical excitation of the cathode. The cathode can include field emissive materials such as carbon nanotubes.
Abstract:
The present invention relates to miniaturized x-ray tubes, that enable radiation treatment by locating the x-ray source within a human body in close vicinity to or inside of the area to be treated with X-rays. Advantageously, the present invention eliminates most of the problems related to the methods based on a radioactive source and offers a method for efficient and controllable radiation treatment.
Abstract:
Röntgenquelle und bildgebendes System Es wird eine Röntgenquelle (1) mit einem evakuierbaren Außengehäuse (3) mit wenigstens einem röntgenstrahldurchlässigen Strahlaustrittsfenster (5), einer Elektronenquelle (7), einer Anode (13) und einem Kollektor (19) zum Auffangen von die Anode durchdringenden Elektronen angegeben. Der Kollektor ist Teil eines elektrischen Stromkreises zum Aufbringen eines negativen Potentials an der Anode, und das Strahlungsfenster ist so angeordnet, dass Röntgenstrahlung (9) durch das Strahlungsfenster hindurch auskoppelbar ist, welche in einem Winkel (a) von 130 Grad bis 230 Grad zur Elektronenstrahlrichtung aus der Anode austritt. Weiterhin wird ein bildgebendes System mit einer erfindungsgemäßen Röntgenquelle, einer Anordnung zur Aufnahme eines zu untersuchenden Objekts und einem Röntgendetektor angegeben.
Abstract:
Die vorliegende Erfindung betrifft ein Filament, insbesondere ein Röntgenkathodenfilament (2), das mindestens ein Emitter- oder Heizfilament (4) aus einem W- basierten Werkstoff mit abstehenden Drahtendabschnitten (6, 8) und den Drahtendabschnitten (6, 8) jeweils zugeordnete Halterungsstifte (12, 14) aus einem hochschmelzenden Metall oder einer hochschmelzenden Metalllegierung zur Fixierung und elektrischen Kontaktierung der Drahtendabschnitte (6, 8) aufweist. Ferner betrifft die Erfindung ein entsprechendes Herstellungsverfahren. Dabei weist mindestens ein Halterungsstift (12, 14) stirnseitig eine Aufnahme (18) auf, in der ein Drahtendabschnitt (6, 8) aufgenommen ist und innerhalb der Aufnahme (18) stoffschlüssig mit dem Halterungsstift (12, 14) verbunden ist. Die stoffschlüssige Verbindung wird über einen Zusatzwerkstoff aus V oder einer V-basierten Legierung, der stoffschlüssig mit dem Drahtendabschnitt (6, 8) sowie stoffschlüssig mit dem Halterungsstift (12, 14) verbunden ist, hergestellt.