Hitachi, Ltd.

Yasuharu Hirai

Akio Yoneyama

Hideo Todokoro

Shigeyuki Hosoki

Shigehiko Yamamoto

Susumu Kawase

A sample which includes a region exhibiting a large density change, such as, bones or lungs and a region exhibiting a small density change, such as, biological soft tissues, and whose measurement is difficult to do for conventional absorption and phase contrast X-ray imaging apparatuses is highly sensitively imaged and observed. In a phase contrast X-ray imaging apparatus using an X-ray interferometer, a reference object whose shape and internal density distribution are analogous to those of a sample and which is known is positioned on an optical path other than an optical path in the interferometer on which the sample is positioned.

X-ray imaging apparatus and method with an X-ray interferometer

To obtain an image that uses both an accurate spatial differential of an object-caused phase shift and the phase shift as contrast at a small observation field of view and under a simplified apparatus configuration , , , . a spatial differential of the object-caused phase shift and the phase shift are arithmetically obtained from the diffraction images of the object formed by simultaneous X-ray diffraction of crystals.

X-ray imaging system

A shock wave detection system used in a vacuum protection system constructed so that a high-speed shutter provided in a vacuum pipe connecting a vacuum system with an experimental apparatus is closed in response to the detection of an atmospheric shock wave that will rush into the vacuum system when an accidental vacuum breakdown occurs at the experimental apparatus. This shock wave detection system comprises an incident light window and an outgoing light window that are provided on the side of the vacuum pipe at the positions opposite to each other, an optical system for entering the light flux linearly polarized or not polarized the incident light window, another optical system for focusing the light flux outgoing from said outgoing light window, an optical fiber for receiving on its surface a diffraction image produced due to the change of light refractivity when the wave front of the shock wave crosses said light flux in the vacuum pipe, and a photo-detector for transforming the diffraction image into a signal for driving the high-speed shutter.

Photoelectric shock wave detection system for vacuum protection

A field emission cathode of the present invention is characterized by the possession of a special layer which is adsorbed onto the surfaces of a tip that is joined to the top of a hairpin-shaped filament. This layer is formed by adsorbing a selected metal via oxygen to a thickness which does not exceed the thickness of the monolayer of atoms. The metal will be selected from chromium, aluminum, cerium, magnesium, titanium, silicon, zirconium or hafnium. The field emission cathode features that the electrons are emitted in a concentrated manner from a particular crystal plane among the crystal planes of the tip. Therefore, it is possible to obtain a field emission cathode having very small emission angle of electrons.

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Tosu, Japan

Yasuharu Hirai