Hitachi, Ltd.

Shuichi Hatakeyama

Yuichiro Ueno

Takahiro Tadokoro

Kouichi Okada

Katsunori Ueno

Yasushi Nagumo

Takahiro Itou

Keisuke Sasaki

Yoshinobu Sakakibara

Tooru Shibutani

Toru Shibutani

Akira Oozone

A radiation monitoring device realizes a high measurement function. Therefore, a radiation monitoring device includes: a radiation detection unit including a phosphor that emits light by incident radiation; a photodetector that converts a single photon or a photon group having a plurality of the single photons generated by the radiation detection unit into an electric pulse signal; and an analysis unit that analyzes the electric pulse signal. The phosphor emits light based on a plurality of light emission phenomena having different decay time constants. The analysis unit includes: a signal discrimination circuit that discriminates the electric pulse signal output from the photodetector; a dose rate calculation circuit that calculates a dose rate of the radiation based on a count rate of the discriminated electric pulse signal; and an application energy calculation circuit that calculates application energy of the radiation based on a peak value of the discriminated electric pulse signal.

Radiation monitoring device

Provided is a radiation monitor and the like capable of appropriately measuring radiation. A radiation monitor () includes: radiation detection units (); optical fibers () that transmit light generated by a plurality of radiation detection elements () to merge; a light detection unit () that converts the light after merging guided to the light detection unit into an electric pulse; a measurement device () that calculates a dose rate of radiation based on a count rate of the electric pulses; and an analysis/display device (). Housings () include a housing () made of a first material and another housing () made of a second material.

Radiation monitor and radiation measurement method

A radiation monitor includes a radiation detection unit detecting radiation, and an optical fiber transmitting photons emitted from a light emitting element of the radiation detection unit, wherein the radiation detection unit includes a first light emitting element generating a photon in response to incident radiation, a chemical compound part having chemical compounds which generate charged particles by nuclear reactions with incident neutrons, and a second light emitting element being located between the first light emitting element and the chemical compound part and generating a photon in response to radiation.

Radiation monitor and method for measuring radiation

A radiation monitoring deviceincludes a scintillator portionwhich emits light whose intensity depends on a dose of incident radiation, an optical fiberwhich transmits photons generated in the scintillator portion, a photoelectric converterwhich converts photons transmitted by the optical fiberto electric signals, a signal counterwhich counts each of electric signals after being converted by the photoelectric converterwith a certain dead time adjusted relative to time width of an irradiation pulse of radiation, a dose calculation unitwhich calculates a dose from a signal count value counted by the signal counter, and a display unitwhich displays a result of measurement calculated by the dose calculation unit

Radiation monitoring device, radiation therapy apparatus, and radiation monitoring method

A screw compressor includes a screw rotor, a casing, and a fluid supply portion to supply fluid in a membrane form into a compression chamber in the casing. The screw rotor has a male and female rotors. A male bore covering the male rotor and a female bore covering the female rotor are formed on the inner surface of the casing. An intersection line, on a higher pressure side, of the male and female bores is defined as a compression cusp. In a bore development view, a trajectory made by the first intersection of an extension line of a female lobe ridge and a male lobe ridge being moved, along with the rotation of the male and female rotors, is defined as a trajectory line. An opening of the fluid supply section to the compression chamber is positioned between the compression cusp and the trajectory line.

Radiation monitor

The present invention includes: a radiation detecting unit including a fluorescent body expressed by the formula ATaO: B, C (in the formula, A is selected from at least one kind of element from among rare-earth elements involving 4f-4f transitions, B is selected from at least one kind of element, different from A, from among rare-earth elements involving 4f-4f transitions, and C is selected from at least one kind of element from among rare-earth elements involving 5d-4f transitions); an optical fiber that transmits photons generated by the fluorescent body; a light detector that converts the photons transmitted via the optical fiberone by one into electrical pulse signals; a counter that counts the number of electrical pulse signals converted by the light detector; an analysis and display devicethat obtains a radiation dose rate on the basis of the number of electrical pulse signals counted by the counter.

A radiation monitorincludes a light-emitting unitwhich generates light having an intensity depending on an amount of an incident radiation, an optical fiberwhich sends a photon generated by the light-emitting unit, a photoelectric converterwhich transmits one electric pulse to one sent photon, a dose calculation devicewhich counts the electric pulse amplified by the photoelectric converterand converts the counted value of the measured electric pulses into a dose of the radiation, and a display device. The dose calculation devicecounts the electric signals converted from the photon by the photoelectric converterto calculate a counting rate, and stops the counting when the counting rate exceeds a predetermined threshold, and performs counting when the counting rate is less than the threshold.

Radiation monitor and method of monitoring radiation

A radiation monitor according to the present invention includes: a radiation sensing unit which includes phosphors emitting a photon with respect to an incident radiation; and a photon sending unit which sends the photon emitted from the phosphors of the radiation sensing unit, wherein the phosphors form a multilayer structure including a first phosphor and a second phosphor, and a photon absorbing layer absorbing a photon emitted from a phosphor is provided between the first phosphor and the second phosphor.

Provided is a radiation monitor, including: a radiation detection unit which includes a radiation detection element, the radiation detection element emitting light of a predetermined light emission wavelength; a light emission unit which emits light of a wavelength different from the light emission wavelength; a wavelength selection unit which passes the light of the light emission wavelength, and is set to a first mode to block the light from the light emission unit; an optical transmission line which transmits the light; a light detection unit which converts the light passing through the wavelength selection unit into an electric pulse; and a control unit which measures a count rate of the electric pulse, and determines whether at least the light emission unit is degraded on the basis of the count rate and a light intensity of the light emission unit.

Radiation monitor and method of analyzing radiation monitor

A radiation therapy apparatus capable of improving the accuracy of a dose distribution includes an X-ray generation device that is provided at an arm portion of a rotation gantry, a radiation detector that is insertable into the body of a patient, a dose calculation device, and a feedback control device. An X-ray generated due to collision of an electron beam with a target in the X-ray generation device is applied to an affected part (cancer) of a patient on a bed. The radiation detector which is insertable into the body detects the X-ray applied to the affected part so as to output a photon to obtain a dose rate and a dose based thereon. The feedback control device either controls the X-ray generation device such that the obtained dose becomes a set dose or controls the radiation generation device such that the obtained dose rate becomes a set dose rate.

Radiation therapy apparatus

The radiation detection device includes a plurality of radiation detectors arranged in a row and is inserted into the body of patient subjected to the X-ray therapy. An X-ray detection signal (photon) is output from each of the radiation detectors that detects the X-ray applied to the patient. The dose rate measurement device separately connected to each of the radiation detectors obtains the dos rate at the position of each radiation detector based on the signals. The irradiation direction determination device determines whether the row of radiation detectors matches the irradiation direction of the X-ray using the dos rate obtained by each of the dose rate measurement devices. When the row of radiation detectors matches the irradiation direction, the energy distribution analysis device obtains an energy distribution using the dose rate at the positions of the radiation detectors by applying, for example, an inverse problem analysis called an unfolding method.

X-ray energy distribution measurement apparatus and X-ray therapy apparatus

The dose measurement device includes: a radiation sensor constituted by a light emitting portion that is made of a polycrystalline scintillator and emits light of intensity dependent on an amount of incident radiation and a cover covering the light emitting portion; an optical fiber that is connected to the radiation sensor and transmits the photons emitted by the polycrystalline scintillator; a photoelectric converter for converting the photons transmitted by the optical fiber into electrical signals; a calculation device for measuring each of the electrical signals through the conversion by the photoelectric converter of each photon, calculating a count rate, and specifying a dose rate; and a display device for displaying measurement results calculated by the calculation device.

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Tokyo, Japan

Shuichi Hatakeyama