Rigaku Corporation

Naohisa Osaka

Masaru Kuribayashi

Kazuhiko Omote

Masahiro Nonoguchi

Yoji Kobayashi

Kiyoshi Ogata

Licai Jiang

Sadayuki Takahashi

Ladislav Pina

Seiichi Hayashi

Takahisa Sato

Makoto Kambe

Bonglea Kim

Yoshihiro Takeda

Tetsuo Kani

Makoto Kanbe

Toru Kobayashi

Kazuaki Shimizu

Vaclav Jelinek

Jiri Marsik

Martin Horvarth

The X-ray generating apparatusapplies an electron beam eonto a targetto generate X-rays x, and includes a permanent magnet lensconfigured to focus the electron beam e, a correction coilprovided on a side of the electron beam ewith respect to the permanent magnet lensand configured to correct a focus position formed by the permanent magnet lensin a traveling direction of the electron beam e, and a targetonto which the focused electron beam is applied. Accordingly, the apparatus configuration can be extremely compact and lightweight in comparison with general apparatuses. Furthermore, by the correction coil, the intensity of the magnetic field can be finely adjusted and the focus position in the traveling direction of the electron beam ecan be finely adjusted.

X-ray generating apparatus

There is provided a target for an X-ray generator, including: a holder part made of an electrically conductive material and having an opening part; a diamond plate air-tightly joined to the holder part so as to close the opening part; a thin film target provided on a surface of the diamond plate, with its outer peripheral part extending to the holder part to be electrically connected to the holder part, wherein the holder part is configured to be electrically connected to a power supply of the X-ray generator, and the diamond plate is incorporated into the X-ray generator with one side disposed in a vacuum atmosphere where the thin film target is formed, and an opposite side thereto disposed at a side where the diamond plate is brought into thermal contact with a refrigerant and cooled.

Target for X-ray generator, method of manufacturing the same and X-ray generator

An industrial X-ray tube formed by accommodating a cathode and anode in a container having an evacuated interior, in which electrons emitted from the cathode are caused to strike the anode and X-rays are emitted from the anode. The cathode is formed from graphite. The graphite is a layered crystal obtained by layering a plurality of carbon hexagonal planes. The graphite is cut based on crystal axes of the carbon hexagonal planes. The resulting cut surface is caused to function as an electron-emitting surface. For example, directions of an a- and b-crystal axis may be set so as to be arbitrary between each of the layers of the carbon hexagonal planes, the graphite may be cut along a surface parallel to the c-axis, and the resulting cut surface may be caused to function as an electron-emitting surface. The graphite may also be cut along a surface orthogonal to the c-axis.

Industrial X-ray tube

A coiled filament for an X-ray tube has a varied coil pitch to obtain a good uniformity of the longitudinal temperature distribution. The filament has a central region including plural turns having a same coil pitch, and end regions which include plural turns each of which has a coil pitch smaller than the coil pitch of the central region. The coil pitches of the plural turns of the end regions are reduced one by one by a same variation from a turn close to the central region toward an outermost turn. A value of &#x394;p/p is within a range of 0.015 to 0.1 and k/n is within a range of 0.3 to 0.8, where p is the coil pitch of the central region, &#x394;p is the coil pitch variation of the end regions, n is a total number of turns of the filament, and k is a sum of numbers of turns of the end regions. The k/n preferably satisfies the following equation:=0.72&#x2212;4.66(&#x394;)&#xb1;0.12.

Filament for X-ray tube and X-ray tube having the same

A filament for an X-ray tube has a varied wire diameter but has a constant coil outside diameter to obtain a good uniformity of the longitudinal temperature distribution of the filament. The filament has a wire diameter d which is gradually reduced from the longitudinal central region to the longitudinal ends while the coil outside diameter D is fixed along the longitudinal direction. The wire is polished at only the inside of the coil to reduce the wire diameter. In order to make the longitudinal temperature distribution uniform as far as possible, the difference &#x394;d between the wire diameter dat the longitudinal central region and the wire diameter dat the longitudinal ends should satisfy the following limitation:&#x394;=0.041 to 0.145.

An X-ray generator includes a cathode having an emitter made of carbon nanotubes which emits electrons by field emission and thus becomes a cold cathode electron emission source. In the invention using the carbon nanotubes, any one of the following three forms is adopted to control the tube current apart from the electron-focusing control. The first form is that a takeoff electrode is disposed near the cathode and the Wehnelt potential and the takeoff electrode potential are controlled independently. The second form is that an electron emission source is disposed behind the cathode and the electron emission source emits electrons which collide against the back of the cathode so that the cathode temperature is controlled in a range of the room temperature to about 100 degrees Celsius to regulate an amount of electron emission from the cathode. The third form is that the cathode has a heater so that the cathode temperature is controlled in a range of the room temperature to about 100 degrees Celsius to regulate an amount of electron emission from the cathode.

X-ray generator

An X-ray generator includes a hermetically sealed main generator unit, and an electron gun and a target housed inside the main generator unit, and bombards the target with electrons emitted from the electron gun and passes an X-ray beam emitted from the surface of the target owing to the bombardment to the exterior through an exit window. An X-ray optical element is provided inside the main generator unit on the output path of the X-ray beam emitted from the target for regulating the X-ray beam and the X-ray beam regulated by the X-ray optical element is passed through the exit window. This configuration improves the durability of the X-ray optical element and enables the length of the X-ray path to the X-ray irradiation point to be shortened so as to suppress attenuation of the emitted X-ray beam by air resistance and thereby reduce power consumption.

A rotating-anode X-ray tube has a rotary pipe rotatably supported in a casing, and a target which is fixed to one end of the rotary pipe and can rotate along with the rotary pipe, the target being cooled by a flow of cooling fluid. A cooling-fluid sealing device is provided between the casing and the rotary pipe and is a mechanical seal. The mechanical seal has a rotary ring which is rotatable along with the rotary pipe and axially movable, a stationary ring fixed to the casing, and pressing means for pressing the rotary ring against the stationary ring. The rotary and the stationary rings come into surface contact with each other within a plane perpendicular to an axis of rotation. The rotary ring is made of carbon and the stationary ring is made of silicon carbide ceramics, both materials being electrically conductive.

Growing community of inventors

Ome, Japan

Naohisa Osaka