Abstract:
An X-ray generator comprises a cathode electrode (15), a grid electrode (17) for controlling an electron beam (e) generated by the cathode electrode (15), a focus electrode (18) for focusing the electron beam (e), and an anode target (14) for emitting X rays by the collision of the electron beam (e). A bias voltage (Vb) is impressed between the cathode electrode (15) and the grid electrode (17) from a bias voltage generating section (20). A tube voltage (Vt) is impressed on the anode target (13) from a tube voltage generating section (19). A voltage dividing section (31) divides the tube voltage (Vt) to generate a focus voltage (Vf). The effect of a variation in voltage on the formation of a focal point of the electron beam is suppressed by impressing such a focus voltage (Vf) on the focus electrode (18).
Abstract:
Die Erfindung betrifft einen Röntgengenerator zur Speisung einer Röntgenröhre (1), die wenigstens zwei Elektronenquellen (11,12) zur Erzeugung unterschiedlich großer Brennflecke an jeweils der gleichen Stelle der Anode aufweist. Dabei läßt sich eine Anpassung des Auflösungsvermögens an die jeweiligen Erfordernisse dadurch erreichen, daß jeder Elektronenquelle je eine Steuereinheit (21,22) zugeordnet ist, die einen von einem Steuersignal an einen Steuereingang der Steuereinheit abhängigen Strom zwischen der zugeordneten Elektronenquelle und der Anode (10) hervorruft, daß beide Steuereinheiten während einer Röntgenaufnahme wirksam sind und daß die Steuersignale und damit das Verhältnis zwischen den von den Elektronenquellen gelieferten mAs-Produkte einstellbar ist.
Abstract:
X-ray stereoscopic cinematography apparatus uses an X-ray tube (1) having a pair of focal points (fr and fl) on the anode (P), from which X-ray beams can be radiated independently. Focal points (fr and fl) are spaced by the inter-ocular distance. The X-ray beams are directed through an object (2) such as a patient, and are received by an image intensifier (3) which emits an optical image received by an optical system (4). The optical beam can be diverted to either or both of cinecameras (5 and 6) for receiving "right" and "left" images. A television camera (7) is arranged to receive both images. The shutters of the cinecameras are synchronised but are 180° out of phase, so that both shutters are never open at the same time. Mode selector (8) can select a stereoscopic radiographic mode, a mono-scopic radiographic mode or a fluoroscopic mode. When the first is selected, X-ray beams are emitted alternately from the focal points (fr and fl) in synchronism with the shutters of the cinecameras (5, 6) so that the first cinecamera (5) receives only "right" images and the other cinecamera (6) receives only the "left" images. In the mono-scopic radiographic mode, X-ray beams are emitted from only one of the two focal points and only one of the cinecameras is activated. In the fluoroscopic mode, X-ray beams from only one of the focal points is emitted, neither cinecamera is activated and the optical image is received only by the television camera (7).
Abstract:
A new structure of an electron emitting device, which is capable of preventing electrical charge of an insulator, and an X-ray generator using the same are presented. The present invention includes includes: a cathode having an electron source emitting electrons; an anode disposed opposite to the cathode; a metal material formed at a center region of the anode to generate X-ray when the electrons are irradiated thereto; a carbon nanotube formed as a electron emitting device in a region of the cathode, which corresponds to a crossing of the cathode and the anode; a gate disposed between the cathode and the anode with spacing in order to control electrons emitted by the carbon nanotube; a pair of focusing electrodes bended to facilitate combination with both ends of the gate, respectively; subracks disposed between the cathode and the focusing electrodes, respectively, and connected to the cathode to have same electric potential as the cathode; and insulators disposed between the subracks and the focusing electrodes. According to the triode electron emitting device of above structure, the insulator is not exposed to an electron emitter to solve the problems such as electric arc and device destroy, etc. Therefore, an X-ray generator stably generating X-ray can be manufactured.
Abstract:
A method for inducing chemical reactions using X-ray radiation comprises generating an irradiation voiume within the interior of a reaction vessel by introducing X-ray radiation into the volume, in which two or more reactants are introduced, With respect to the two or more reactants and any subsequentiy created intermediate reactani or reactants, the aggregate extent to which the foregoing reactants are to be ionized to any degree is selectively controlled, and the average degree of ionization in the irradiation volume, from partial to total, of that portion of the foregoing reactants which is to be ionized is selectively controlled, through control of the fiuence and energy of the X-ray radiation, to thereby induce selective reactions of reactants to occur in the irradiation volume. One or more reactants may be delivered through a double-wailed pipe containing X-ray shielding to prevent their premature irradiation before being infected into the irradiation volume.
Abstract:
The present invention provides for an improved scanning process with a stationary X- ray source arranged to generate X-rays from a plurality of X-ray source positions around a scanning region, a first set of detectors arranged to detect X-rays transmitted through the scanning region, and at least one processor arranged to process outputs from the first set of detectors to generate tomographic image data. The X-ray screening system is used in combination with other screening technologies, such as NQR-based screening, X-ray diffraction based screening, X-ray back-scatter based screening, or Trace Detection based screening.
Abstract:
A dual energy X-ray source for use in an explosive detection system includes only a single power supply and only a single X-ray tube. The X-ray tube includes only two : electron guns and only a single anode. Each electron gun has its own grid and cathode: The X-ray source switches between producing a higher energy X-ray and producing a lower energy X-ray at a frequency of at least 4000 Hz.
Abstract:
An X-ray scanning apparatus comprises a number of multi-focus X-ray tubes (25) spaced around an axis X and arranged to emit X-rays through an object on the axis which are detected by sensors (52). Each tube (25) can emit X-rays from a plurality of source positions. In each scanning cycle, in which each of the source positions in each of the tubes is used once, the ordering of the positions used is arranged so as to minimize the thermal load on the tubes (25). This is achieved by ensuring that each source position is non-adjacent to the previously active one and the next active one.
Abstract:
An imaging module includes a plurality of cathodes and respective gates, each cathode configured to generate a separate beam of electrons directed across a vacuum chamber and each gate matched to at least one respective cathode to enable and disable each separate beam of electrons from being directed across the vacuum chamber, A target anode is fixed within the vacuum chamber and arranged to receive the separate beam of electrons from each of the plurality of cathodes and, therefrom, generate a beam of x-rays. A deflection system is arranged between the plurality of cathodes and the target anode to generate a variable magnetic field to control a path followed by each of the separate beams of electrons to the target anode.