Shimadzu Corporation

The University of Tokyo

Tokai National Higher Education and Research System

Tetsuo Furumiya

Junichi Ohi

Masayuki Nakazawa

Hiroyuki Takahashi

Kenji Shimazoe

Koji Tojo

Masafumi Furuta

Hideki Tomita

Tatsuya Ikehara

A gas measurement apparatus includes an optical resonator that resonates light, a light source that generates light for irradiation of the optical resonator, and a photodetector that detects light taken out of the optical resonator. The optical resonator includes a plurality of mirrors, a holding member, a hollow tubular member, a hollow tubular member, and a temperature adjustment instrument. The holding member is lower in thermal expansion coefficient than the hollow tubular member. The hollow tubular member includes a portion higher in thermal conductivity than the holding member and a bellows higher in elasticity than a first portion. The hollow tubular member is equal to or higher than the hollow tubular member in thermal conductivity, and is provided as far as positions of the plurality of mirrors on an inner side of the bellows.

Measurement apparatus

A radiation detection device () is used in a nuclear medicine diagnosis apparatus, and includes a plurality of scintillators (), a semiconductor light-receiving device (SiPM), a position detection circuit (), and a timing detection circuit (). Each of the scintillators converts a gamma ray emitted from a subject () into fluorescence. The semiconductor light-receiving device is provided corresponding to each of the scintillators and converts the fluorescence converted by a corresponding one of the scintillators into an electrical signal. The position detection circuit specifies a gamma ray detection position in the scintillators based on the electrical signal from the semiconductor light-receiving device. The timing detection circuit is connected to an anode of the semiconductor light-receiving device, and specifies time information corresponding to a time of occurrence of an event in which the gamma ray is detected.

Radiation detection device and nuclear medicine diagnosis apparatus including the same

This photodetector () includes a first discriminator () configured to discriminate a first signal output from a plurality of photoelectric conversion elements (), a second discriminator () configured to discriminate a second signal based on signals output from the plurality of photoelectric conversion elements, and a trigger signal generator () configured to generate a trigger signal, the trigger signal indicating that light to be detected is incident based on discrimination results of the first discriminator and the second discriminator.

Photodetector

A radiation detector includes a plurality of semiconductor light receiving elements and a plurality of reflection elements that segment a scintillator array. A plurality of respective segment areas by the reflection elements. A plurality of amplifiers amplify signals obtained from respective semiconductor light receiving elements. The scintillator array includes a plurality of scintillators. The radiation detector provides a first accumulator per segment area, and a first trigger generation circuit per segment area. The first trigger generation circuit generates a first trigger of the multiple signal added by the first accumulator for each of the plurality of respective segment areas. An encoder generates a single first trigger signal based on the first trigger.

Radiation detector

A radiation detector that improves accurately a fluorescence emission-time. A limiter circuit instead of a low-pass filter and a high-pass filter removes a noise component of the amplifier output. The limiter circuit blocks passing through the amplification signal when the amplification signal output from the amplifier a is lower than the limit level. Accordingly, a noise component output not related to the fluorescence detection from the amplifier a is blocked by the limiter circuit L and is unable to reach to the addition circuit. When the amplification signal output from the amplifier a is larger than the limit level, the limiter circuit L passes through such amplification signal; so that the signal, which is related to a fluorescence detection, that the amplifier a outputs can be absolutely input into the fluorescence emission-time calculation element.

Radiation detector and radiation imaging device comprising same

One embodiment of the disclosure includes an A-D conversion circuit connected to a photodiode for providing a silicon photomultiplier that with enhanced detection accuracy and a time resolution. A current generated upon photon detection by the photodiode partially flows into another photodiode adjacent to the photodiode arranged in parallel via a resistor. At this time, the current is charged into a parasitic capacitance adjacent to the photodiode, and thereafter is discharged. However, the discharged current cannot flow toward an output terminal by the A-D conversion circuit, and also cannot switch the A-D conversion circuit. Consequently, the construction of the disclosure can detect light with no influence of the current discharged from the parasitic capacitance. As a result, the disclosure achieves a silicon photomultiplier with high detection accuracy and a satisfactory time resolution.

Silicon photomultiplier with improved detection accuracy

The disclosure has one object to provide a radiation tomography apparatus of a low price that facilitates a design change of a detector ring to suppress costs of development. The radiation tomography apparatus according to the disclosure includes a plurality of modules configured to receive detected data from different radiation detectors. Then, the modules each send and receive the detected data to and from one another, thereby sharing the detected data and counting the number of coincidence events. That is, when manufacturing radiation tomography apparatus, merely wiring the coincidence modules achieves implementation of the coincidence unit. This allows manufacturing the radiation tomography apparatus without new development of a substrate for performing coincidence. Consequently, the radiation tomography apparatus of a low price can be provided with suppressed costs of the development.

Radiation tomography apparatus

With a pulse-height analyzer, a reference-pulse generator generates a reference pulse of a given pulse height for a given period of time when an analog radiation pulse inputted to a comparator is higher than an initial threshold. A capacitor and a resistor receive the reference pulse, and then increase an increment threshold for the given period of time from the initial threshold to the given pulse height. Then the increment threshold is set as a reference voltage of the comparator. A pulse time width of the analog radiation pulse is determined through measuring a period of time from timing where the analog radiation pulse exceeds the initial threshold to timing where the analog radiation pulse being attenuated falls below the increment threshold.

Pulse height analyzer and nuclear medicine diagnosis apparatus provided with the same

The limiter circuit of this invention is a limiter circuit which, by switching action of a pair of transistors, allows passage of only signal voltage components of an input signal voltage included in ranges of an upper limit signal voltage and a lower limit signal voltage. With this construction, the pair of transistors carry out comparisons between the input signal voltage and threshold signal voltages and line switching at the same time. Therefore, there is no influence of propagation delay speed, and no switching noise occurs at times of line switching. Since diodes are not used, a high-speed limiter circuit can be manufactured.

Limiter circuit

According to a spurious pulse generator of this invention, integrating circuits are provided at a plurality of stages for carrying out integrating operations about time and outputting a spurious pulse, the integrating circuits being constructed to input a voltage value for controlling a crest value which is a peak swing of the spurious pulse to an amplifier forming an integrating circuit at a most upstream stage when a switching element is ON, and to input a constant voltage value when the switching element is OFF. As a result, the voltage value before ON-state and after ON-state of the switching element does not change but remains a constant voltage value, thereby obtaining a desired spurious pulse.

Spurious pulse generator

A radiation detector of this invention includes a pulse width modulation circuit for binarizing an analog electrical pulse outputted from a detector cell with a predetermined threshold, and modulating it into a digital electrical pulse, and a data superposer for outputting an incident position pulse train by superposing incident position pulses and concerning the position of the detector cell on which the radiation has fallen, and the digital electrical pulse detected by the radiation. Thus, position information which has conventionally been added after output of digital electrical pulse can be added into the digital electrical pulse. Therefore, compared with the conventional technique of adding position information after digital electrical pulse and transmitting the position information, the position of the radiation incident on the detector cell can be detected in a short time.

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Kyoto, Japan

Tetsuo Furumiya