Hitachi, Ltd.

Atsushi Yamagoshi

Hiroshi Kitaguchi

Takeshi Shima

Shigeru Izumi

Hiroshi Kamimura

Katsutoshi Satoh

Noriyuki Sadaoka

Tetsuya Matsui

Takeshi Watanabe

Kouji Kuwabara

Tarou Takagi

Shouhei Numata

Akihisa Kaihara

Koji Agatsuma

An X-ray sensor signal processing circuit and method used in an industrial X-ray CT apparatus for processing an output signal of a semiconductor X-ray sensor which detects a pulsed X-ray emitted from an accelerator and passed through an object to be inspected. The circuit includes a first resistor having one terminal connected to the X-ray sensor and an other terminal connected to ground, a first capacitor having one end terminal connected to a connection point of the X-ray sensor and the first resistor, an operational amplifier having an inverting input connected to an other terminal of the first capacitor, and an integrator having a second resistor and a second capacitor each connected to the operational amplifier in parallel. The circuit is configured so that at least bias conditions of the X-ray sensor and the first capacitor are returned to a steady state after irradiation of the pulsed X-ray.

X-ray sensor signal processor and X-ray computed tomography system using the same

To provide a radioactive gas measurement apparatus that is simply constructed and can efficiently measure Xe-133 in a radioactive gas on-line under the condition that the radioactive gas is mixed with interference N-13, an apparatus is provided for measuring a radiation emitted from Xe-133, including an anticoincidence counter circuitthat conducts counting if it receives an output of a main detectorwhen it does not receive outputs of scintillation detectorsand, and a gate circuit, a plate-shaped semiconductor detector is used as the main detector, and a material not emitting a characteristic X ray in the range from 70 to 90 keV is used for a shielding structure. In particular, the thickness of the semiconductor detectoris set to fall within a range from 2 mm to 7 mm, thereby improving the analysis precision.

Radioactive gas measurement apparatus and failed fuel detection system

An X-ray CT apparatus having X-ray irradiator for irradiating an X-ray to an object to be inspected, an X-ray sensor for detecting an X-ray passed through the object to be inspected, an X-ray sensor signal processing circuit for processing an output signal from the X-ray sensor, and a CT control apparatus for reconstructing an image of the object to be inspected on the basis of an output signal of the X-ray sensor processed by the X-ray sensor signal processing circuit. The X-ray sensor signal processing circuit removes a DC component from the output signal of the X-ray sensor and integrates the output signal of the X-ray sensor having the DC component removed therefrom.

An X-ray CT apparatus having X-ray irradiator for irradiating an X-ray to an object to be inspected, an X-ray sensor for detecting an X-ray passed through the object to be inspected, an X-ray sensor signal processing circuit for processing an output signal from the X-ray sensor, and a CT control apparatus for reconstructing an image of the object to be inspected on the basis of an output signal of the X-ray sensor processed by the X-ray sensor signal processing circuit. The X-ray sensor signal processing circuit includes a filter for removing a DC component from the output signal of the X-ray sensor, and an integration circuit for integrating the output signal of the X-ray sensor from which the DC component is removed by the filter.

An X-ray CT apparatus having X-ray irradiator for irradiating an X-ray to an object to be inspected, an X-ray sensor for detecting an X-ray passed through the object to be inspected, an X-ray sensor signal processing circuit for processing an output signal from the X-ray sensor, and a CT control apparatus for reconstructing an image of the object to be inspected on the basis of the output signal of the X-ray sensor processed by the X-ray sensor signal processing circuit. The X-ray sensor signal processing circuit includes a filter for removing a DC component from the output signal of the X-ray sensor and a circuit for obtaining a difference between a voltage corresponding to a current including a dark current generated in the X-ray sensor by incidence of the X-ray and a voltage corresponding to the dark current.

An X-ray CT apparatus having X-ray irradiator for irradiating an X-ray to an object to be inspected, an X-ray semiconductor sensor for detecting an X-ray passed through the object to be inspected, an X-ray sensor signal processing circuit for processing an output signal from the X-ray semiconductor sensor, and a CT control apparatus for reconstructing an image of the object to be inspected on the basis of the output signal of the X-ray semiconductor sensor processed by the X-ray sensor signal processing circuit. The X-ray sensor signal processing circuit includes a filter for removing a DC component from the output signal of the X-ray semiconductor sensor, and an integration circuit for integrating an output signal of the X-ray semiconductor sensor from which the DC component is removed by the filter.

An X-ray sensor signal processor including capacitorsfor removing DC components (dark currents) from output signals of semiconductor sensorstodetecting pulse-like X-rays passed through an object, and integrators (each of which is constituted by a combination of an operational amplifiera resistorand a capacitor) for integrating the output signals of the X-ray sensors after removal of the DC components by the capacitorsBy this, a value proportional to the average number of photons in X-rays can be obtained even in the case where a small number of incident photons are given, and an X-ray CT system using the X-ray sensor signal processor.

X-ray sensor signal processor and x-ray computed tomography system using the same

An X-ray sensor signal processor including capacitors for removing DC components (dark currents) from output signals of semiconductor sensors to detecting pulse-like X-rays passed through an object, and integrators (each of which is constituted by a combination of an operational amplifier a resistor and a capacitor ) for integrating the output signals of the X-ray sensors after removal of the DC components by the capacitors By this, a value proportional to the average number of photons in X-rays can be obtained even in the case where a small number of incident photons are given, and an X-ray CT system using the X-ray sensor signal processor.

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Hitachi, Japan

Atsushi Yamagoshi