Abstract: The present invention includes: a radiation detecting unit including a fluorescent body expressed by the formula ATaO4: 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 fiber 3 one 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 device 6 that obtains a radiation dose rate on the basis of the number of electrical pulse signals counted by the counter.

Abstract: A nitride semiconductor device includes a GaN-based semiconductor layer; and an insulating film provided on a first surface of the GaN-based semiconductor layer, the insulating film containing O atoms, and other constituent atoms other than O. An interface between the GaN-based semiconductor layer and the insulating film has a terminating species which terminates a dangling bond of a Ga atom, the terminating species has an outermost electron shell in which one electron is deficient from an allowed number of outermost electrons, and is an atom or molecule having stronger bond to the Ga atom than a H atom, an amount of Ga—O bonds is greater than an amount of bonds between the Ga atoms and the other constituent atoms.

Abstract: 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.

Abstract: A nitride semiconductor device is provided, comprising: a first nitride semiconductor layer of a first conductivity-type; a second nitride semiconductor layer of a second conductivity-type provided above the first nitride semiconductor layer; a junction region of a first conductivity-type which is provided to extend in a direction from a front surface of the second nitride semiconductor layer to the first nitride semiconductor layer and has a doping concentration NJFET equal to or higher than that of the first nitride semiconductor layer; and a source region of a first conductivity-type which is provided more shallowly than the junction region and has a doping concentration equal to or higher than the doping concentration NJFET, wherein a dopant of the source region is an element with an atomic weight larger than that of a dopant in the junction region.

Abstract: A radiation monitor 1 includes a light-emitting unit 10 which generates light having an intensity depending on an amount of an incident radiation, an optical fiber 20 which sends a photon generated by the light-emitting unit 10, a photoelectric converter 30 which transmits one electric pulse to one sent photon, a dose calculation device 40 which counts the electric pulse amplified by the photoelectric converter 30 and converts the counted value of the measured electric pulses into a dose of the radiation, and a display device 50. The dose calculation device 40 counts the electric signals converted from the photon by the photoelectric converter 30 to 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.

Abstract: A method for manufacturing a nitride semiconductor device includes: selectively ion-implanting an element that is other than p-type impurities and n-type impurities into a first region in a first primary surface of a gallium nitride layer so as to generate crystal defects in the first region; selectively ion-implanting a p-type impurity into a second region in the gallium nitride layer, the second region being shallower than the first region in a depth direction and being within the first region in a plan view; and thermally treating said gallium nitride layer that has been ion-implanted with said element and said p-type impurity so as to thermally diffuse said p-type impurity in the second region into a third region that is within the first region and that surrounds a bottom and sides of the second region.

Abstract: 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.

Abstract: A manufacturing method of a vertical GaN-based semiconductor device having: a GaN-based semiconductor substrate; a GaN-based semiconductor layer including a drift region having doping concentration of an n type impurity, which is lower than that of the GaN-based semiconductor substrate, and is provided on the GaN-based semiconductor substrate; and MIS structure having the GaN-based semiconductor layer, an insulating film contacting the GaN-based semiconductor layer, and a conductive portion contacting the insulating film, the method includes: implanting an n type dopant in a back surface of the GaN-based semiconductor substrate after forming of the MIS structure, and annealing the GaN-based semiconductor substrate after the implanting of the n type dopant.

Abstract: A nitride semiconductor device includes a nitride semiconductor layer, channel cells in the nitride semiconductor layer, a source lead region of a second conductivity type in the nitride semiconductor layer, and a source electrode on a side where a first main surface of the nitride semiconductor layer is located. The channel cells each include a well region of a first conductivity type and a source region of the second conductivity type in contact with the well region. The source lead region is connected to the source region. The channel cells extend in a first direction in a planar view from a normal direction of the first main surface, and arranged in a second direction intersecting with the first direction in the planar view. The source electrode is in contact with the source lead region away from a line of the channel cells arranged in the second direction.

Abstract: A nitride semiconductor device includes a transistor having a channel region in a gallium nitride-based semiconductor layer. The transistor includes: a gate insulating film provided above the gallium nitride-based semiconductor layer; an intermediate layer arranged between the gallium nitride-based semiconductor layer and the gate insulating film, having a band gap smaller than that of the gate insulating film, and having a band offset with the gallium nitride-based semiconductor layer; a gate electrode provided on the gate insulating film; a first conductivity type source region provided in the gallium nitride-based semiconductor layer; and a source electrode provided on the gallium nitride-based semiconductor layer and being in contact with the source region. The intermediate layer is arranged at a position opposed to the gate electrode through the gate insulating film and avoids a source contact region in which the source electrode is in contact with the source region.

Abstract: 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.

Abstract: The nitride semiconductor device includes: a nitride semiconductor layer; a first conductivity type source region provided on a surface of the nitride semiconductor layer; a second conductivity type well region provided in the nitride semiconductor layer and adjacent to the source region in a first direction parallel to the surface and in a second direction intersecting with the first direction; a trench located on the opposite side of the source region with the well region sandwiched therebetween in the first direction; a first conductivity type impurity region located between the well region and the trench; an insulating film provided on a bottom surface of the trench; a gate insulating film provided on the well region; and a gate electrode provided from on the insulating film to on the gate insulating film. A thickness of the insulating film is larger than a thickness of the gate insulating film.

Abstract: Provided is a radiation monitor and the like capable of appropriately measuring radiation. A radiation monitor (100) includes: radiation detection units (11, 12); optical fibers (13p, 13q) that transmit light generated by a plurality of radiation detection elements (11a, 12a) to merge; a light detection unit (14) that converts the light after merging guided to the light detection unit into an electric pulse; a measurement device (15) that calculates a dose rate of radiation based on a count rate of the electric pulses; and an analysis/display device (16). Housings (11b, 12b) include a housing (11b) made of a first material and another housing (12b) made of a second material.

Abstract: 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.

Abstract: Provided is a manufacturing method of a semiconductor device including a vertical MOSFET having a planar gate. The manufacturing method of a semiconductor device includes forming a n-type gallium nitride layer on a gallium nitride monocrystalline substrate, and forming an impurity-implanted region that contains impurities at a uniform concentration in a direction parallel to a main surface of the gallium nitride monocrystalline substrate, by ion-implanting the impurities into the n-type gallium nitride layer, where the impurities include at least one type selected from among magnesium, beryllium, calcium and zinc. Here, at least part of the impurity-implanted region serves as a channel forming region of the vertical MOSFET.

Abstract: 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.

Abstract: A vertical semiconductor device is provided, including a transistor region and a Schottky diode region, and having, in a gallium nitride layer in the Schottky diode region, a first well region, a diode trench portion that is provided in direct contact with the first well region in an array direction in which the transistor region and the Schottky diode region are arrayed, a first upper drift region that is connected to the bottom of the diode trench portion, a lower drift region that is connected to the bottom of the first well region and a bottom of the first upper drift region, and a conductive portion that is connected to an upper portion of the first upper drift region.

Abstract: A radiation monitoring device 1 includes a scintillator portion 10 which emits light whose intensity depends on a dose of incident radiation, an optical fiber 20 which transmits photons generated in the scintillator portion 10, a photoelectric converter 30 which converts photons transmitted by the optical fiber 20 to electric signals, a signal counter 40 which counts each of electric signals after being converted by the photoelectric converter 30 with a certain dead time adjusted relative to time width of an irradiation pulse of radiation, a dose calculation unit 50 which calculates a dose from a signal count value counted by the signal counter 40, and a display unit 60 which displays a result of measurement calculated by the dose calculation unit 50.

Abstract: A diode is provided, the diode including: a semiconductor layer of a first conductivity type, configured to have a trench structure and be an epitaxial layer of a wide gap semiconductor; a semiconductor layer of a second conductivity type, configured to be at least in contact with a side wall of the trench structure and be an epitaxial layer of the wide gap semiconductor; and an electrode configured to be in contact with the semiconductor layer of the first conductivity type and the semiconductor layer of the second conductivity type, on the semiconductor layer of the first conductivity type and the semiconductor layer of the second conductivity type.

Abstract: 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.