Hamamatsu Photonics Kabushiki Kaisha

Hamamatsu-photonics K.k.

Koichiro Oba

Motohiro Suyama

Tetsuya Morita

Yoshihiko Kawai

Hiroyuki Kyushima

Yutaka Hasegawa

Toru Hirohata

Minoru Niigaki

Masuo Ito

Yoshihiko Mizushima

Kenichi Sugimoto

Toshihiro Suzuki

Tomoko Suzuki

Junichi Takeuchi

Tsuneo Ihara

Wilfried Schoeps

David Taqqu

A liquid scintillation counterserving as an optical measurement apparatus includes: an HPDa charge amplifiera voltage amplifiera comparatora countera multi-channel analyzera displayand the like. The HPDhas a photocathodeand an APDfor outputting a signal that corresponds to the number of incident photons. The comparatoroutputs a logic pulse signal, serving as a comparison result signal, only when the signal outputted from the HPDand amplified by the charge amplifierand voltage amplifieris larger than a prescribed threshold value. This threshold value is set larger than an output signal that is outputted when a single photoelectron is emitted from the photocathodeand smaller than another output signal that is outputted when two or more photoelectrons are emitted.

Optical measurement apparatus and method for optical measurement

An optical measurement apparatusprimarily includes: a photon detection unitfor detecting incident photons, a time signal output unitfor outputting a time signal, and a storage unitfor storing the time signal outputted from the time signal output unitwhen the photon detection unitdetects photons. The photon detection unitincludes a HPDhaving a photocathodeand an APD, a TZ amplifier, a peak holding circuit, and an A/D converter. The time signal output unitincludes a timerand a counter. The storage unitincludes a comparatorand a memory. When photons impinge on the HPD, a trigger signal is outputted from the comparator, causing the photon-number outputted from the A/D converterand the time data outputted from the counterto be stored in the memory

A photomultiplier tube which obtains a large decrease in manufacture time, prevents generation of gas within the envelope, prevents deterioration of electron multiplier assembly (dynodes), and greatly reduces noise. The envelope includes an all-metal cylindrical sidewall, at one end of which is an annular, flange-shaped, metal sealing area. The stem of the photomultiplier tube has another annular flange-shaped, metal sealing area. These two sealing areas are welded together. Also a metal exhaust tube is connected to the stem by resistance welding. The metal exhaust tube is severed using pinch-off seal at the final stage of the photomultiplier tube production.

Photomultiplier tube having a metal-made sidewall

A junction, such as a Schottky junction, is formed between a conductive electrode and a semiconductor. A bias voltage is applied between the conductive electrode and an outward-emission-side electrode formed on the semiconductor at the side opposite to the junction. Upon illumination, photoelectrons are internally emitted in the conductive electrode into the semiconductor, transported through the semiconductor, and emitted outward from the semiconductor surface, which has been so treated as to reduce the surface barrier height. The semiconductor is semi-insulating, or a p-n junction is formed therein.

Photoemitter

An apparatus is provided for detecting the one-dimensional position of incidence of particle beams. The apparatus comprises

Apparatus for detecting the position of incidence of particle beams

An instrument measures fluorescence which has occurred in a sample stimulated by X rays. The instrument consists of a laser device, an X-ray pulse generation tube excited by the laser pulse from the laser device, a light sensor for detecting fluorescence in the sample, a reference timing pulse generator, a time-to-voltage converter to indicate the time of fluorescence and a multichannel analyzer to sum the frequency of times that the designated voltage is issued from the time-to-voltage converter in each voltage level during measurement.

Instrument to measure fluorescence which has occurred in a sample

A system for calibrating the time axis of an X-ray streak tube comprising a light source for generating a train of light pulses and an X-ray tube including a photocathode for receiving the light pulses. Upon receiving the light pulses, the X-ray tube generates a train of X-rays which excite the photocathode of the streak tube causing it to emit an electron beam. The electron beam is scanned by a sweep voltage synchronized with the light pulses and applied across deflection electrodes in the streak tube. The deflected beam impinges on the phosphor screen of the streak tube where the time interval of the streak image is measured.

System for calibrating the time axis of an X-ray streak tube

A high speed light detection tube consists of a planar photoelectron source of transparent type, a photoelectron collection electrode arranged in parallel with the photoelectron source and an acceleration electrode of transmission type arranged in parallel with the photoelectron source in a space between the photoelectron source and the photoelectron collection electrode. The potential distribution has been set so that the photoelectrons passing through the acceleration electrode can be incident on the photoelectron collection electrode at a constant speed or near value.

High speed light detection tube

An X-ray shadow graph device comprising a light source, an X-ray tube, light connection means, a sample, an image recording device, and sample excitation means, which obtains a transmission image or transmission diffraction image of X rays with a time resolution of 10 ps or less when the sample is stimulated by a light pulse or voltage pulse signal with an extremely short duration time of approximately 1 ps.

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Hamamatsu, Japan

Koichiro Oba