Abstract: There is provided a vitrified bond super-abrasive grinding wheel including: a core; and a super-abrasive grain layer provided on the core, wherein the super-abrasive grain layer includes a plurality of super-abrasive grains and a vitrified bond that joins the plurality of super-abrasive grains, and the vitrified bond has a plurality of bond bridges located between the plurality of super-abrasive grains to join the plurality of super-abrasive grains, not less than 80% of the plurality of super-abrasive grains are joined to the super-abrasive grains adjacent thereto by the bond bridges, and not less than 90% of the plurality of bond bridges in a cross section of the super-abrasive grain layer have a thickness equal to or smaller than an average grain size of the super-abrasive grains, and have a length greater than the thickness.

Abstract: There is provided a vitrified bond super-abrasive grinding wheel including: a core; and a super-abrasive grain layer provided on the core, wherein the super-abrasive grain layer includes a plurality of super-abrasive grains and a vitrified bond that joins the plurality of super-abrasive grains, and the vitrified bond has a plurality of bond bridges located between the plurality of super-abrasive grains to join the plurality of super-abrasive grains, not less than 80% of the plurality of super-abrasive grains are joined to the super-abrasive grains adjacent thereto by the bond bridges, and not less than 90% of the plurality of bond bridges in a cross section of the super-abrasive grain layer have a thickness equal to or smaller than an average grain size of the super-abrasive grains, and have a length greater than the thickness.

Abstract: A photomultiplier according to an embodiment of the present invention has a sealed container the interior of which is maintained in a vacuum state, and an electron multiplier unit housed in the sealed container, and the sealed container is partly constructed of ceramic side tubes, on the assumption that the photomultiplier is used under high-temperature, high-pressure environments. The photomultiplier further has a structure for fixing an installation position of the electron multiplier unit relative to the sealed container, for improvement in anti-vibration performance.

Abstract: A photomultiplier according to an embodiment of the present invention has a sealed container the interior of which is maintained in a vacuum state, and an electron multiplier unit housed in the sealed container, and the sealed container is partly constructed of ceramic side tubes, on the assumption that the photomultiplier is used under high-temperature, high-pressure environments. The photomultiplier further has a structure for fixing an installation position of the electron multiplier unit relative to the sealed container, for improvement in anti-vibration performance.

Abstract: The super abrasive wheel includes a core rotating around a rotation axis and a super abrasive layer bonded to the core. The core has a first surface and a second surface located opposite to the first surface. An annular first protrusion portion protruding in the direction away from the first surface is provided at a portion of the second surface that is surrounded with the super abrasive layer. A reference surface is provided in the second surface on the inside of the first protrusion portion. The height from the reference surface to the first protrusion portion is denoted as A. A top portion having the height B from the reference surface is provided at a portion of the second surface between the first protrusion portion and the super abrasive layer. The height B is greater than the height A.

Abstract: The super abrasive wheel includes a core rotating around a rotation axis and a super abrasive layer bonded to the core. The core has a first surface and a second surface located opposite to the first surface. An annular first protrusion portion protruding in the direction away from the first surface is provided at a portion of the second surface that is surrounded with the super abrasive layer. A reference surface is provided in the second surface on the inside of the first protrusion portion. The height from the reference surface to the first protrusion portion is denoted as A. A top portion having the height B from the reference surface is provided at a portion of the second surface between the first protrusion portion and the super abrasive layer. The height B is greater than the height A.

Abstract: An electron tube of the present invention includes: a vacuum vessel including a stem portion made of quartz and formed with an opening; a lid portion connected to the stem portion via a joining member made of aluminum so as to seal the opening, having a recess portion depressed to a vacuum side in the opening, and made of Kovar; a voltage applying section arranged in the vacuum vessel; and wiring for electrically connecting the voltage applying section and the lid portion.

Abstract: An electron tube of the present invention includes: a vacuum vessel including a stem portion made of quartz and formed with an opening; a lid portion connected to the stem portion via a joining member made of aluminum so as to seal the opening, having a recess portion depressed to a vacuum side in the opening, and made of Kovar; a voltage applying section arranged in the vacuum vessel; and wiring for electrically connecting the voltage applying section and the lid portion.

Abstract: A photomultiplier excellent in vibration resistance and improved in pulse linearity characteristic and time-response. The fourth, and sixth to ninth dynodes (Dy4, Dy6 to Dy9) have a similar shape to that of the second dynode (Dy2). The third and fifth dynodes (dy3, Dy5) are smaller than the dynode (Dy2). The first to tenth dynodes (Dy1 to Dy10) are so arranged that the dynode inner space path defined between opposed dynodes is perpendicular to the tube axis (X). The anode (A) is a mesh anode (A), and is opposed to the dynode (Dy2) with respect to the tube axis (X).

Abstract: A photomultiplier that prevents rattling between the dynodes and the base plates, the parts being fixed securely to achieve excellent vibration resistance. The dynode of the second stage (Dy2) includes a curved surface (Dy2A) having an arcuate cross-section and a flat surface (Dy2B) formed continuously and flush with the curved surface. The curved surface (Dy2A) and flat surface (Dy2B) make up the secondary electron emitting surface. Side walls (Dy2C) erected from the curved surface (Dy2A) are formed through a pressing process on either lengthwise end of the curved surface (Dy2A). First ear portions (Dy2D) extend outward from both side walls (Dy2C). Second ear portions (Dy2E) extend outward from both lengthwise ends of the flat surface (Dy2B). The first and second ear portions (Dy2D and Dy2E) are not parallel to each other but form a fixed angle.

Abstract: A photomultiplier tube excellent in vibration resistance and having an anode with good pulse linearity characteristic. The photomultiplier tube has a mesh anode (A) composed of an anode frame (A11) and a mesh electrode (A12) supported and surrounded by the anode frame (A11). The central portion of one long side (A11B) of the anode frame (A11) serves as an electron converging part (F). The inner side of the anode frame (A11) swells toward the inner part of the anode (A), more from the middle of the long side (A11B) toward the corners of the anode frame (A11) along the long side (A11B), and therefore the thickness of the anode frame (A11) increases from the middle of the long side (A11) to the corners along the long side (A11B).

Abstract: A photomultiplier tube excellent in vibration resistance and having an anode with good pulse linearity characteristic. The photomultiplier tube has a mesh anode (A) composed of an anode frame (A11) and a mesh electrode (A12) supported and surrounded by the anode frame (A11). The central portion of one long side (A11B) of the anode frame (A11) serves as an electron converging part (F). The inner side of the anode frame (A11) swells toward the inner part of the anode (A), more from the middle of the long side (A11B) toward the corners of the anode frame (A11) along the long side (A11B), and therefore the thickness of the anode frame (A11) increases from the middle of the long side (A11) to the corners along the long side (A11B).

Abstract: A photomultiplier excellent in vibration resistance and improved in pulse linearity characteristic and time-response. The fourth, and sixth to ninth dynodes (Dy4, Dy6 to Dy9) have a similar shape to that of the second dynode (Dy2). The third and fifth dynodes (dy3, Dy5) are smaller than the dynode (Dy2). The first to tenth dynodes (Dy1 to Dy10) are so arranged that the dynode inner space path defined between opposed dynodes is perpendicular to the tube axis (X). The anode (A) is a mesh anode (A), and is opposed to the dynode (Dy2) with respect to the tube axis (X).

Abstract: A photomultiplier that prevents rattling between the dynodes and the base plates, the parts being fixed securely to achieve excellent vibration resistance. The dynode of the second stage (Dy2) includes a curved surface (Dy2A) having an arcuate cross-section and a flat surface (Dy2B) formed continuously and flush with the curved surface. The curved surface (Dy2A) and flat surface (Dy2B) make up the secondary electron emitting surface. Side walls (Dy2C) erected from the curved surface (Dy2A) are formed through a pressing process on either lengthwise end of the curved surface (Dy2A). First ear portions (Dy2D) extend outward from both side walls (Dy2C). Second ear portions (Dy2E) extend outward from both lengthwise ends of the flat surface (Dy2B). The first and second ear portions (Dy2D and Dy2E) are not parallel to each other but form a fixed angle.

Abstract: The present invention relates to a light-receiving module of a heat-resistant, vibration-resistant type for use in petroleum exploration or the like, and a radiation detecting apparatus equipped with the light-receiving module. The light-receiving module comprises a photomultiplier having a faceplate and a stem opposing each other, a bleeder circuit board provided so as to sandwich the stem together with the faceplate and electrically connected to the photomultiplier, a module case provided so as to accommodate the photomultiplier and the bleeder circuit board, said module case having an opening for exposing the faceplate of the photomultiplier, a step provided on an inner surface of the module case, and a stopper seated on the step, defining the position of the photomultiplier in the module case.