Abstract: A radiation detector includes: a first scintillator including a first end surface and a second end surface; a second scintillator including a first end surface and a second end surface; a first photodetector detects light emitted from the first end surface of each of the first and second scintillators; a second photodetector c detects light emitted from the second end surface of each of the first and second scintillators; and a position specifying unit configured to specify each radiation incident position on which each radiation has been incident in each of the first and second scintillators, wherein an area of the first end surface of the first scintillator is smaller than an area of the second end surface of the first scintillator, and an area of the first end surface of the second scintillator is larger than an area of the second end surface of the second scintillator.

Abstract: A radiation detector includes: a first scintillator; a second scintillator; a first photodetector; a second photodetector; a first light quantity adjusting member; a second light quantity adjusting member; and a position specifying unit specifies each radiation incident position in each of the first and second scintillators. Optical transmittance of the first light quantity adjusting member is smaller than optical transmittance of an optical path between the second end surface of the first scintillator and the second photodetector. Optical transmittance of the second light adjusting member is smaller than optical transmittance of an optical path between the first end surface of the second scintillator and the first photodetector.

Abstract: A radiation detector includes: a first scintillator including a first end surface and a second end surface; a second scintillator including a first end surface and a second end surface; a first photodetector detects light emitted from the first end surface of each of the first and second scintillators; a second photodetector c detects light emitted from the second end surface of each of the first and second scintillators; and a position specifying unit configured to specify each radiation incident position on which each radiation has been incident in each of the first and second scintillators, wherein an area of the first end surface of the first scintillator is smaller than an area of the second end surface of the first scintillator, and an area of the first end surface of the second scintillator is larger than an area of the second end surface of the second scintillator.

Abstract: A radiation detector includes: a first scintillator; a second scintillator; a first photodetector; a second photodetector; a first light quantity adjusting member; a second light quantity adjusting member; and a position specifying unit specifies each radiation incident position in each of the first and second scintillators. Optical transmittance of the first light quantity adjusting member is smaller than optical transmittance of an optical path between the second end surface of the first scintillator and the second photodetector. Optical transmittance of the second light adjusting member is smaller than optical transmittance of an optical path between the first end surface of the second scintillator and the first photodetector.

Abstract: A radiation detector comprises a scintillator 2A having a first end face 11, a second end face 13 disposed on a side opposite from the first end face 11, and a plurality of light-scattering surfaces 21 formed with an interval therebetween along a first direction P from the first end face 11 side to the second end face 13 side; a first photodetector 12 optically coupled to the first end face 11; and a second photodetector 14 optically coupled to the second end face 13. The light-scattering surfaces 21 are formed so as to intersect the first direction P. The light-scattering surfaces 21 include modified regions 21R formed by irradiating the inside of the scintillator 2A with laser light.

Abstract: A radiation detector is provided with a scintillator 2A containing a plurality of modified regions 21 and a plurality of photodetectors or a position-sensitive photodetector optically coupled to a surface of the scintillator 2A. The plurality of modified regions 21 are formed by irradiating an inside of a crystalline lump which will act as the scintillator 2A with a laser beam and three-dimensionally dotted and have a refractive index different from a refractive index of a surrounding region within the inside of the scintillator 2A.

Abstract: A radiation detector comprises a scintillator 2A having a first end face 11, a second end face 13 disposed on a side opposite from the first end face 11, and a plurality of light-scattering surfaces 21 formed with an interval therebetween along a first direction P from the first end face 11 side to the second end face 13 side; a first photodetector 12 optically coupled to the first end face 11; and a second photodetector 14 optically coupled to the second end face 13. The light-scattering surfaces 21 are formed so as to intersect the first direction P. The light-scattering surfaces 21 include modified regions 21R formed by irradiating the inside of the scintillator 2A with laser light.

Abstract: A radiation detector is provided with a scintillator 2A containing a plurality of modified regions 21 and a plurality of photodetectors or a position-sensitive photodetector optically coupled to a surface of the scintillator 2A. The plurality of modified regions 21 are formed by irradiating an inside of a crystalline lump which will act as the scintillator 2A with a laser beam and three-dimensionally dotted and have a refractive index different from a refractive index of a surrounding region within the inside of the scintillator 2A.

Abstract: A depth of interaction detector with uniform pulse-height comprises a multi-layer scintillator obtained by coupling at least two scintillator cells on a plane and then stacking the planar coupled scintillator cells, in layers, up to at least two stages and a light-receiving element connected to the bottom face of each scintillator cell of this multi-layer scintillator, wherein the detector is provided with a means for discriminating the position of a scintillator cell, which receives radiant rays and emits light rays and a means for making, uniform, the quantity of the light emitted from each scintillator cell and received by the light-receiving element.

Abstract: The radiation three-dimensional position detector of the present invention comprises a scintillator unit (10), a light receiving element (20) and an operation section (30). The scintillator unit is disposed on the light incident plane of the light receiving element, wherein the scintillator unit is comprised of four layers of scintillator arrays, each layer being composed of scintillator cells arrayed in 8 row ?8 column matrix. The scintillator cell produces scintillation light corresponding to the radiation absorbed thereby. The optical characteristic of a partition material for separating neighboring scintillator cells, which faces at least one same side face is different between a scintillator cell Ck1,m,n included in one scintillator array layer (k1-th layer) and a scintillator cell Ck2,m,n included in the other scintillator array layer (k2-th layer).

Abstract: A PET apparatus is provided, which ensures excellent quantitativeness by properly correcting the influence of scattered radiation while improving the resolution of a reconstructed image and keeping good photon pair detection sensitivity. A determining section 52 determines whether a straight line connecting the light-receiving surfaces 15b of a pair of photon detectors 15a which have simultaneously detected a photon pair crosses any one of slice collimators 21n. When it is determined that the straight line crosses none of the slice collimators 21n, the corresponding coincidence counting information is accumulated by a first coincidence counting information storage section 53 to generate a signal sinogram. When it is determined that the straight line crosses one of the slice collimators 21n, the corresponding coincidence counting information is accumulated by a second coincidence counting information storage section 54 to generate a scatter sinogram.

Abstract: A rotating ceptor 20 provided inside a detector portion 10 includes nine shield plates S1 to S9 disposed in parallel to each other in between adjacent detector rings R, acts as a collimator, and allows only those photon pairs that have traveled approximately parallel to a slice plane to be made incident upon photon detectors D located behind the rotating ceptor 20. Each of the shield plates S is not formed annularly, and provided near the measurement field of view 1 of part of N photon detectors D that constitute each of the detector rings R. The rotating ceptor 20 is rotatable about its center axis. Each of the shield plates S is provided with bar-shaped radiation source insertion holes 20a and 20b for allowing a bar-shaped positron emission radiation source 3 to be inserted therein and supported thereby.

Abstract: A depth of interaction detector with uniform pulse-height comprises a multi-layer scintillator obtained by coupling at least two scintillator cells on a plane and then stacking the planar coupled scintillator cells, in layers, up to at least two stages and a light-receiving element connected to the bottom face of each scintillator cell of this multi-layer scintillator, wherein the detector is provided with a means for discriminating the position of a scintillator cell, which receives radiant rays and emits light rays and a means for making, uniform, the quantity of the light emitted from each scintillator cell and received by the light-receiving element.

Abstract: A PET apparatus (1) includes a detecting section (10). Each cylindrical detector (13n) of the detecting section (10) has a plurality of block detectors (141 to 14M) arranged on the same circumference on a place perpendicular to a central axis (CAX) in the form of a ring. Each block detector (14m) is a two-dimensional position detector which detects the two-dimensional incident position of a photon incident on a light-receiving surface 15b. Each slice collimator (21n) extends to a rear portion of a corresponding one of cylindrical detectors (13n) through the space between adjacent cylindrical detectors (13n) and (13n+1) and is integrally fixed by a holding plate (22) at the rear portion.

Abstract: The radiation three-dimensional position detector of the present invention comprises a scintillator unit (10), a light receiving element (20) and an operation section (30). The scintillator unit is disposed on the light incident plane of the light receiving element, wherein the scintillator unit is comprised of four layers of scintillator arrays, each layer being composed of scintillator cells arrayed in 8 row—8 column matrix. The scintillator cell produces scintillation light corresponding to the radiation absorbed thereby. The optical characteristic of a partition material for separating neighboring scintillator cells, which faces at least one same side face is different between a scintillator cell Ck1,m,n included in one scintillator array layer (k1-th layer) and a scintillator cell Ck2,m,n included in the other scintillator array layer (k2-th layer).

Abstract: A method of introducing a substance into plant tissue whereby the substance is introduced into the tissue of a plant having branches through the branch, wherein the substance is absorbed through conductive tissue of the branch while inhibiting means is carried out in order to inhibit transpiration through a leaf on the branch or to inhibit water requirement by the leaf.

Abstract: A first detector group 1 and a second detector group 2, disposed opposite to each other and detecting gamma ray pairs resulting from electron-positron pair annihilation, are each constituted by two two-dimensional radiation detectors 101, and 102, 201, and 202, and arranged so that a prescribed arrangement spacing L2 is established between the scintillator arrays 11 and 21. Furthermore, the coincidence counting circuit 50 of the signal processing circuit 5 is constituted so as to carry out coincidence counting for diagonally disposed detectors as well as oppositely disposed detectors. Accordingly, the are a between the ranges of the fields of view resulting from opposite detectors is supplemented by a range of the field of view resulting from diagonally disposed detectors. Consequently, it becomes possible to attain a positron imaging device wherein the range of the field of view is efficiently expanded, and the simplification and cost reduction of the device are realized.

Abstract: A PET apparatus includes a detecting unit; slice septa for transmitting therethrough flying photons nearly perpendicular to the center axis; a slice septa position determining section for determining whether or not the slice septa exist in the measurement space side of at least one of the pair of photon detectors; a two-dimensional projection image storage section for storing coincidence-counting information of the photon pair obtained by the pair of photon detectors; a three-dimensional projection data storage section for storing coincidence counting information obtained by the pair of photon detectors; and an image reconstructing section for reconstruction an image indicative of a spatial distribution of a frequency at which photon pairs are emitted in the measurement space.

Abstract: A rotating ceptor 20 provided inside a detector portion 10 includes nine shield plates S1 to S9 disposed in parallel to each other in between adjacent detector rings R, acts as a collimator, and allows only those photon pairs that have traveled approximately parallel to a slice plane to be made incident upon photon detectors D located behind the rotating ceptor 20. Each of the shield plates S is not formed annularly, and provided near the measurement field of view 1 of part of N photon detectors D that constitute each of the detector rings R. The rotating ceptor 20 is rotatable about its center axis. Each of the shield plates S is provided with bar-shaped radiation source insertion holes 20a and 20b for allowing a bar-shaped positron emission radiation source 3 to be inserted therein and supported thereby.

Abstract: A PET apparatus is provided, which ensures excellent quantitativeness by properly correcting the influence of scattered radiation while improving the resolution of a reconstructed image and keeping good photon pair detection sensitivity. A determining section 52 determines whether a straight line connecting the light-receiving surfaces 15b of a pair of photon detectors 15a which have simultaneously detected a photon pair crosses any one of slice collimators 21n. When it is determined that the straight line crosses none of the slice collimators 21n, the corresponding coincidence counting information is accumulated by a first coincidence counting information storage section 53 to generate a signal sinogram. When it is determined that the straight line crosses one of the slice collimators 21n, the corresponding coincidence counting information is accumulated by a second coincidence counting information storage section 54 to generate a scatter sinogram.