JP5827076B2 - Electrode structure - Google Patents

Description

  The present invention relates to an electrode structure.

  Conventionally, as an electrode structure formed by laminating a plurality of electrodes, an electrode structure is known in which insulation between adjacent electrodes is ensured using an insulator or the like, and an interval between adjacent electrodes is made uniform. . For example, Patent Document 1 below describes a configuration in which an alumina insulating layer is formed on a dynode plate, and a plurality of dynode plates are stacked via the insulating layer. Further, in Patent Document 2 and Patent Document 3 below, an insulating member is provided between adjacent dynodes, and a protrusion provided on the frame of the dynode and a hole provided on the frame of the insulating member are fitted. In addition, a configuration in which a plurality of dynodes are stacked is described. Patent Document 4 below describes a configuration in which a concave portion and a convex portion are provided on the entire surface of an electrode, and a concave portion and a convex portion between adjacent electrodes are fitted to each other to laminate a plurality of electrodes. Yes.

British Patent 1401969 JP 2008-293917 A JP 2009-152121 A Japanese Patent No. 4615816

  However, all of the configurations described in Patent Documents 1 to 4 have a fitting structure or an insulating structure on the surface of the electrode (dynode). For this reason, the ratio of the effective area | region of functional parts, such as an electron multiplication part with respect to the surface area of an electrode, reduces according to the area of the area | region in which the fitting structure or the insulation structure was provided.

  Then, this invention is made | formed in view of such a situation, and it aims at providing the electrode structure which has a structure which can suppress the reduction | decrease of the effective area | region of the functional part in an electrode.

  In order to solve the above problems, an electrode structure according to the present invention is an electrode structure formed by laminating a plurality of electrodes provided with openings through which charged particles pass, and the plurality of electrodes are provided with openings. And an opening forming portion having conductivity, including first and second electrodes adjacent to each other in the stacking direction, and a protrusion projecting in the stacking direction is provided at a peripheral portion of the first electrode, A concave portion that is recessed in a direction in which the convex portion protrudes is provided at the peripheral portion of the electrode, and the first and second electrodes are provided on the convex portion provided on the first electrode and the second electrode. Are fitted to each other, and at least one of the convex portion provided on the first electrode and the concave portion provided on the second electrode has an insulating property. The second electrodes are insulated from each other.

  This electrode structure includes a convex portion provided at the peripheral portion of the first electrode of the plurality of electrodes and a concave portion provided at the peripheral portion of the second electrode, and is provided on the first electrode. The convex portion and the concave portion are fitted together with at least one of the convex portion and the concave portion provided in the second electrode having an insulating property. For this reason, since the first and second electrodes are positioned at the peripheral edge and reliably insulated, the ratio of the electrode in the region (effective region) in which the opening (functional portion) through which the charged particles pass is provided. Adjacent first and second electrodes can be stacked without being reduced.

  Moreover, it is preferable that a convex part and a recessed part have insulation. In this case, since both the convex portion and the concave portion have insulating properties, the electrodes adjacent in the stacking direction are more reliably insulated.

  The plurality of electrodes are preferably made of a conductive material, and an insulating layer is preferably provided on at least one of the convex portion and the concave portion. The conductive material is preferably a metal material, and the insulating layer is preferably made of a film that insulates the surface of the metal material. Further, the film for insulating the surface of the metal material is preferably an oxide film obtained by oxidizing the surface of the metal material. In this case, since the adhesion between the insulating layer and the electrode is high, the electrodes adjacent in the stacking direction are more reliably insulated.

  The plurality of electrodes may further include a base portion made of an insulating material and provided with an opening corresponding to the position where the opening is provided, and the opening forming portion may be made of a conductive layer disposed on the base portion. preferable. Moreover, it is preferable that a base part contains a peripheral part and a convex part and a recessed part are provided in the base part. In this case, since the convex portion and the concave portion are made of the insulating material since the convex portion and the concave portion are made of the insulating material, the loss of the insulating region such as the dropping of the insulating material in the convex portion and the concave portion is eliminated. Can do. As a result, the electrodes adjacent in the stacking direction are more reliably insulated.

  Moreover, it is preferable that the depth of a recessed part is larger than the thickness of the electrode provided with the said recessed part. In this case, the fitting length of the convex part and the concave part fitted to each other is increased, and the electrodes adjacent to each other in the stacking direction are more firmly fixed.

  Moreover, it is preferable that the length of the convex part in the stacking direction is equal to or greater than the depth of the concave part fitted into the convex part. In this case, since the tip of the convex portion is in contact with the bottom surface of the concave portion, the electrodes adjacent in the stacking direction are more reliably positioned in the stacking direction. Further, in the stacking direction, the length of the convex portion is equal to or greater than the depth of the concave portion fitted into the convex portion, so that the regions provided with openings through which the charged particles of the electrodes adjacent in the stacking direction pass are surely formed. Spaced apart.

  Each of the plurality of electrodes is provided with a convex portion protruding in the stacking direction and a concave portion recessed in the direction in which the convex portion protrudes at the peripheral portion, and the convex portion and the concave portion are mutually in the stacking direction. It is preferable that they are arranged to face each other. In this case, in the electrode, the region where the convex portion is provided and the region where the concave portion is provided are collected. For this reason, compared with the case where a convex part and a recessed part are provided in another position, a convex part and a recessed part can be enlarged and the electrodes adjacent to a lamination direction are supported more stably.

  Moreover, it is preferable that the convex part and recessed part provided in the some electrode are arrange | positioned along the lamination direction. In this case, since the portions where the convex portions and the concave portions of the adjacent electrodes are fitted together form a column and exhibit a columnar structure, the electrodes adjacent to each other in the stacking direction are more firmly fixed.

  Further, it is preferable that three or more convex portions and concave portions are provided at intervals in the peripheral edge portion of the electrode. In this case, the protrusions and the recesses are fitted at three or more locations, so that the electrodes adjacent to each other in the stacking direction in the stacking direction, one direction orthogonal to the stacking direction, and the other direction orthogonal to the one direction. Are positioned relative to each other.

  Further, the plurality of electrodes are polygonal in a plan view, and two or more convex portions and concave portions are preferably provided on one side of the electrode, and one or more are provided on the side opposite to the one side. . In this case, the convex portion and the concave portion are fitted at three or more locations on a pair of opposing sides, so that in the stacking direction, one direction orthogonal to the stacking direction and the stacking direction and the other direction orthogonal to the one direction, The electrodes adjacent in the stacking direction are positioned with respect to each other.

  Moreover, it is preferable that the convex part and the recessed part are respectively provided over the whole peripheral part. In this case, the convex portion and the concave portion are fitted over the entire peripheral edge portion of the electrode, whereby the electrodes adjacent in the stacking direction are more firmly fixed.

  Further, the plurality of electrodes are polygonal in plan view, the convex portion is located at the corner of the electrode provided with the convex portion, and the concave portion is located at the corner of the electrode provided with the concave portion. Preferably it is located. In this case, the convex portions and the concave portions are positioned at the corner portions of the electrodes, whereby the electrodes are more stably supported, and the electrodes adjacent in the stacking direction are more reliably separated from each other.

  Further, the convex portion is provided along the peripheral edge portion of the electrode provided with the convex portion, and the concave portion is provided along the peripheral edge portion of the electrode provided with the concave portion, and the convex to be fitted. It is preferable that the part and the concave part are in contact with each other in the direction in which the convex part protrudes and in both directions along the peripheral part where the convex part is provided. In this case, the electrodes adjacent to each other in the stacking direction are fitted in a pair of convex portions and concave portions so that the convex portions protrude and the three directions along the peripheral portion provided with the convex portions. Positioned relative to each other. For this reason, the number of convex parts and concave parts necessary for positioning electrodes adjacent to each other in the stacking direction can be suppressed.

  Further, the convex portion is provided along the peripheral edge portion of the electrode provided with the convex portion, and the concave portion is provided along the peripheral edge portion of the electrode provided with the concave portion, and the convex to be fitted. It is preferable that the part and the concave part are in contact with each other in any one direction along the protruding direction of the convex part and the peripheral part where the convex part is provided. In this case, the convex portion and the concave portion are small as compared with the case where they are positioned in the three directions of the two directions along the direction in which the convex portion protrudes and the peripheral portion provided with the convex portion. For this reason, even if it is a narrow space, a convex part and a recessed part can be provided.

  The plurality of electrodes further include a third electrode adjacent to the second electrode, and a peripheral portion of the second electrode is further provided with a convex portion protruding in a direction in which the concave portion is depressed, The peripheral edge of the electrode is provided with a recess that is recessed in the direction in which the protrusion provided on the second electrode protrudes, and the second and third electrodes are connected to the protrusion provided on the second electrode. The recesses provided in the third electrode are fitted to each other to be positioned, and at least one of the projections provided in the second electrode and the recesses provided in the third electrode has an insulating property. It is preferable that the second and third electrodes are insulated from each other.

  In this case, the convex part provided in the 2nd electrode is provided with the convex part provided in the peripheral part of the 2nd electrode among several electrodes, and the recessed part provided in the peripheral part of the 3rd electrode. And a convex part and a recessed part are fitted in the state in which at least one of the recessed part provided in the 3rd electrode has insulation. For this reason, since the second and third electrodes are positioned at the peripheral edge and reliably insulated, the ratio of the electrode in the region (effective region) provided with the opening (functional portion) through which the charged particles pass is determined. Electrodes adjacent in the stacking direction can be stacked without being reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the reduction | decrease of the effective area | region of the functional part in an electrode can be suppressed.

It is a general | schematic end elevation along the pipe-axis direction of a photomultiplier tube provided with the electrode structure which concerns on this embodiment. It is a disassembled perspective view which shows the electrode structure of FIG. (A) is a front view of the recessed part and convex part of the dynode of FIG. 1, (b) is an end elevation along the III (b) -III (b) line of (a). It is a perspective view which shows the electrode structure of FIG. (A) is the figure which expanded the fitting part of the electrode structure of FIG. 4, (b) is an end elevation along the V (a) -V (a) line | wire of (a). It is a figure which shows an example of the manufacture process of the dynode of FIG. It is a figure which shows an example of the manufacture process of the dynode of FIG. It is a figure which shows the IV characteristic of the dynode of FIG. It is a figure which shows the other example of the electrode structure of FIG. It is a figure which shows arrangement | positioning of the convex part and recessed part which concern on a modification. It is a figure which shows arrangement | positioning of the convex part and recessed part which concern on a modification. It is a figure which shows arrangement | positioning of the convex part and recessed part which concern on a modification. It is a figure which shows arrangement | positioning of the convex part and recessed part which concern on a modification. It is a figure which shows arrangement | positioning of the convex part and recessed part which concern on a modification. It is a figure which shows arrangement | positioning of the convex part and recessed part which concern on a modification. It is a figure which shows the shape of the convex part and recessed part which concern on a modification. It is a figure which shows the shape of the convex part and recessed part which concern on a modification. It is a figure which shows the shape of the convex part and recessed part which concern on a modification. It is a figure which shows the modification of the dynode of FIG. It is a schematic end view along the electron incident axis direction of the electron beam excitation light source to which the electrode structure according to the present invention is applied. It is a schematic end elevation along the electron incident axis direction of the electron gun of the X-ray tube to which the electrode structure according to the present invention is applied.

  Hereinafter, preferred embodiments of an electrode structure according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic end view of a photomultiplier tube including an electrode structure according to an embodiment of the present invention along the tube axis direction. In FIG. 1, hatching is omitted to clearly show each part. The photomultiplier tube 1 is a device that converts incident light into an electrical signal and outputs it, and is, for example, a TO-8 size photomultiplier tube. This photomultiplier tube 1 has a metal side tube 2, and a substantially rectangular light receiving face plate formed of a light transmissive material such as glass at an opening on one end side of the metal side tube 2. 3 is hermetically fixed by fusion or the like. On the inner surface of the light receiving face plate 3, a photocathode 3a that converts incident light into electrons is provided.

  On the other hand, a rectangular stem 4 made of an insulating material such as glass is attached to the opening on the other end side of the metal side tube 2. More specifically, a metal tubular member 5 surrounding the side surface of the stem 4 is airtightly fixed by fusion or the like, and a flange 5a formed at one end of the tubular member 5 and a metal side tube The other end of 2 is joined airtightly by welding or the like. As described above, the electrode structure 15 and the anode 8 are disposed inside the vacuum vessel V constituted by the metal side tube 2, the light receiving face plate 3, the stem 4, and the like. Here, in the description of the photomultiplier tube 1, the tube axis direction is the z-axis direction, one direction orthogonal to the z-axis direction is the x-axis direction, and the direction orthogonal to the plane defined by the x-axis direction and the z-axis direction is The y-axis direction is assumed. Further, the light receiving face plate 3 side in the z-axis direction is one side, and the stem 4 side is the other side.

  The electrode structure 15 is formed by laminating the focusing electrode 6 and at least two dynodes 10 (electrodes) in the z-axis direction. The plurality of dynodes 10 are stacked in the z-axis direction (stacking direction) to form the electron multiplier section 7. Each dynode 10 is provided with a plurality of electron passage holes 11 for multiplying incident electrons in parallel with each other along the y-axis direction. The convergence electrode 6 is a plate-like member provided between the photocathode 3 a and the electron multiplier 7. A plurality of slits 61 extending in the y-axis direction are formed in the focusing electrode 6 at substantially equal intervals in the x-axis direction. Details of the electrode structure 15 will be described later.

  Furthermore, a plurality of anodes 8 extending in the y-axis direction are arranged between the electron multiplier section 7 and the stem 4 in the vacuum container V. Each anode 8 is connected to one end of a stem pin 12 for extracting an output signal, and the other end of each stem pin 12 penetrates the stem 4 in an airtight manner and protrudes to the outside.

  The photomultiplier action of the photomultiplier tube 1 configured as described above will be described. When incident light transmitted through the light-receiving face plate 3 is irradiated onto the photocathode 3a, photoelectrons are emitted into the vacuum vessel V. The emitted photoelectrons are focused on the dynode 10 disposed on the most side through the slit 61 of the focusing electrode 6. As a result, the photoelectrons are multiplied by the dynode 10 while passing through the electron passage hole 11 located between the light receiving face plate 3 and the anode 8, and secondary electron groups are emitted from the dynode 10 arranged on the most other side. The The secondary electron group reaches the anode 8, and an output signal is transmitted through the stem pin 12 connected to the anode 8.

  Next, the electrode structure 15 will be described in detail with reference to FIGS. FIG. 2 is an exploded perspective view showing the electrode structure 15 of FIG. 3A is a partially enlarged view of the dynode 10 of FIG. 2, and FIG. 3B is an end view taken along line III (b) -III (b) of FIG. FIG. 4 is a perspective view showing a laminated structure of the electrode structure 15 of FIG. 5A is an enlarged view of a fitting portion of the multi-stage dynode 10 of FIG. 4, and FIG. 5B is an end view taken along the line V (a) -V (a) of FIG. .

  As shown in FIG. 2, the converging electrode 6 is a substantially rectangular plate-shaped member electrode. The convergence electrode 6 includes a slit forming portion 18 in which a slit 61 is formed and a frame portion 16 surrounding the slit forming portion 18. On the outer peripheral edge of the frame portion 16, a concave portion 17 is provided that is recessed on one side from the back surface 6 b of the focusing electrode 6 along the z-axis direction. For one side of each side of the frame portion 16, one concave portion 17 is provided at a position opposite to the concave portion 17 on the opposite side substantially at the center of each side, and for the other side, the concave portion 17 on the opposite side is mutually connected. Two concave portions 17 are provided on each side at predetermined intervals at opposite positions.

  The dynode 10 is an electrode of a substantially rectangular plate-shaped member formed of a metal material M (conductive layer) such as aluminum, stainless steel, Cu—Be, or copper. The dynode 10 includes a main surface 10a that is one surface orthogonal to the z-axis direction and a back surface 10b that is the other surface orthogonal to the z-axis direction. The dynode 10 integrally includes an electron passage hole forming part EM (opening forming part), a frame part 21, a plurality of projecting parts 22, and a charge supplying part 26. The electron passage hole forming portion EM is a portion provided with a plurality of slit-like electron passage holes 11 extending in parallel with each other along the y-axis direction. The frame part 21 surrounds the electron passage hole forming part EM and defines the peripheral part of the dynode 10, and the outer shape thereof is substantially rectangular.

  For one side of each side of the frame portion 21, one projection 22 is provided at a position opposite to the projection 22 of the opposite side at the approximate center of each side, and for the other side, the projection of the opposite side. Two protrusions 22 are provided at predetermined intervals on each side at positions opposite to each other. The protruding portion 22 is a portion provided on the peripheral edge of the dynode 10 and includes a first portion 22a and a second portion 22b. The first portion 22 a is a portion that protrudes in parallel to the frame portion 21 from the outer peripheral edge of the frame portion 21 toward the outside. The second portion 22b is a portion that is provided at the tip of the first portion 22a in the protruding direction and extends to one side along the z-axis direction. Thus, the protrusion 22 exhibits an L shape in a cross section defined by the z-axis direction and the protrusion direction of the first portion 22a. For one side of each side of the frame portion 21, one protrusion 22 is provided in the approximate center of each side, and for the other side, two protrusions 22 are provided on each side at a predetermined interval. ing. And the convex part 23 and the recessed part 24 are provided in the 2nd part 22b of each protrusion part 22. As shown in FIG. That is, both the convex portion 23 and the concave portion 24 are provided along the peripheral edge portion of the dynode 10. The charge supply part 26 is a part that protrudes from the frame part 21 in substantially the same length as the protrusion part 22 in parallel with the frame part 21 from one opposite side of the frame part 21 toward the outside. The charge supply part 26 is a part for supplying a voltage and current for secondary electron multiplication to the electron passage hole forming part EM.

  As shown in FIGS. 2 and 3, the convex portion 23 extends from the distal end in the extending direction of the second portion 22 b to one side along the z-axis direction. The convex portion 23 has the same thickness as the second portion 22b, an outer surface 23b that is an outer surface orthogonal to the thickness direction, and an inner surface 23c that is an inner surface orthogonal to the thickness direction, Side end surfaces 23d and 23d, which are a pair of surfaces that intersect the outer side surface 23b and the inner side surface 23c and extend in the z-axis direction, and a front end surface 23e that is a front end surface of the convex portion 23 are provided. Further, the convex portion 23 in a direction orthogonal to the surface defined by the projecting direction of the first portion 22a and the z-axis direction (hereinafter referred to as “width direction” in the description of the projecting portion 22, the convex portion 23, and the concave portion 24). The length (hereinafter referred to as “width”) is smaller than the width of the second portion 22b.

  The recess 24 is provided at the end on the other end side of the second portion 22b, and is recessed on one side along the z-axis direction. The recess 24 is a bottom surface 24b that is a surface orthogonal to the z-axis direction, a side surface 24c that is a surface orthogonal to the thickness direction of the second portion 22b, and a pair of surfaces that intersect the side surface 24c and extend in the z-axis direction. It is formed by the side end faces 24d and 24d. The concave portion 24 has a shape corresponding to the convex portion 23, and the convex portion 23 and the concave portion 24 can be fitted to each other. In addition, the width of the recess 24 is smaller than the width of the second portion 22 b, and the depth (length in the z-axis direction) of the recess 24 is larger than the thickness of the metal material M. The convex portion 23 and the concave portion 24 are provided in the second portion 22b so as to face each other in the z-axis direction. The length of the convex portion 23 in the z-axis direction is equal to or greater than the depth of the concave portion 24.

  Further, an insulating layer 23a is provided on the inner side surface 23c, the side end surfaces 23d and 23d and the tip end surface 23e of the convex portion 23, and an insulating layer 24a is provided on the bottom surface 24b, the side surface 24c and the side end surfaces 24d and 24d of the concave portion 24. ing. The insulating layer 23a and the insulating layer 24a are oxide films obtained by oxidizing a metal material that forms the dynode 10, for example. When the dynode 10 is made of aluminum, the insulating layer 23a and the insulating layer 24a are films made of alumina. Further, a raised portion 27 is provided at the inner boundary portion between the first portion 22 a and the second portion 22 b of the protruding portion 22.

  In the adjacent dynodes 10 and 10 having such a shape, the concave portion 24 of the dynode 10 on one side and the convex portion 23 of the dynode 10 on the other side are provided at positions facing each other. The adjacent dynodes 10 and 10 are stacked on each other by fitting the concave portion 24 of the dynode 10 on one side and the convex portion 23 of the dynode 10 on the other side. In a state where the adjacent dynodes 10 and 10 are fitted together, the tip surface 23e of the convex portion 23 of the other dynode 10 is in contact with the bottom surface 24b of the concave portion 24 of the one dynode 10 and the convex surface of the other dynode 10 is convex. The side end surfaces 23d and 23d of the portion 23 are in contact with the side end surfaces 24d and 24d of the concave portion 24 of the dynode 10 on one side, and the inner side surface 23c of the convex portion 23 of the dynode 10 on the other side is the concave portion 24 of the dynode 10 on the one side. In contact with the side surface 24c.

  Similarly, the concave portion 17 of the focusing electrode 6 and the convex portion 23 of the dynode 10 arranged on the most side are provided at positions facing each other. Then, the converging electrode 6 and the dynode 10 arranged on the one side are stacked together by fitting the concave portion 17 of the converging electrode 6 with the convex portion 23 of the dynode 10 arranged on the most side. As a result, the electrode structure 15 shown in FIG. 4 is formed. In addition, the adjacent dynodes 10 and 10 are insulated from each other by fitting the convex portions 23 and the concave portions 24 of the adjacent dynodes 10 and 10 through the insulating layer 23a and the insulating layer 24a. The convex portion 23 of the dynode 10 and the concave portion 17 of the converging electrode 6 arranged on the most side are fitted to each other via an insulating layer 23a provided on the convex portion 23, whereby the converging electrode 6 and the dynode 10 Is insulated.

  As shown in FIGS. 4 and 5, in the electrode structure 15, each dynode 10 has the same shape, and therefore the portion where the convex portion 23 and the concave portion 24 of the adjacent dynodes 10 and 10 are fitted together. Each of the (fitting portions) is aligned on a straight line along the stacking direction. As a result, the fitting portion forms a columnar structure as a whole. Further, since the bottom surface 24b of the concave portion 24 of the dynode 10 on one side of the adjacent dynodes 10 and 10 is in contact with the tip surface 23e of the convex portion 23 of the dynode 10 on the other side, the adjacent dynodes 10 and 10 are Positioned in the direction. Further, since the side surface 24c of the concave portion 24 of the dynode 10 on one side and the inner side surface 23c of the convex portion 23 of the dynode 10 on the other side are in contact, the adjacent dynodes 10 and 10 are positioned in the protruding direction of the first portion 22a. Is done. Further, since the side end surfaces 24d, 24d of the concave portion 24 of the dynode 10 on one side and the side end surfaces 23d, 23d of the convex portion 23 of the dynode 10 on the other side are in contact, the adjacent dynodes 10, 10 are positioned in the width direction. Is done.

  Further, the separation distance between adjacent dynodes 10 and 10 is the length from the main surface 10a to the tip surface 23e of the convex portion 23 along the stacking direction, and from the back surface 10b to the bottom surface 24b of the concave portion 24 along the stacking direction. The distance is subtracted by the depth (the length of the fitting portion between the convex portion 23 and the concave portion 24 when the tip surface 23e of the convex portion 23 is not in contact with the bottom surface 24b of the concave portion 24).

  Next, an example of a method for manufacturing the dynode 10 will be described with reference to FIGS. First, as shown in FIG. 6A, a plate-shaped metal material M is prepared. The metal material M is a single conductive layer made of aluminum, stainless steel, Cu—Be, copper or the like. Then, as shown in FIG. 6B, the metal material M is bent to one side along the z-axis direction at a predetermined position surrounding the rectangular flat portion p in the central region of the metal material M. Thereby, the protrusion part 22 and the convex part 23 are formed. Subsequently, as shown in FIG. 6C, by providing a plurality of cuts parallel to the y-axis direction in the flat portion p at substantially equal intervals in the x-axis direction, the electron passage hole forming portion EM and the frame portion 21 in the flat portion p. Then, bending is performed so that one end side of the electron multiplier piece s sandwiched between two adjacent cuts is located on one side from the main surface Ma and the other end side is located on the other side from the main surface Ma.

  Next, as shown in FIG. 7A, both surfaces of the bent electron multiplying piece s are pressed to process the electron multiplying piece s into a desired shape. Then, as shown in FIG. 7B, the bent portion of the protrusion 22 is pressed from the outside along the extending direction of the protrusion 22 to form the recess 24. At this time, the pressed portion is pushed inward, and the raised portion 27 is formed inside the bent portion of the protrusion 22. The dynode 10 is produced as described above. In addition, although the above-mentioned shaping | molding process and a processing process are all performed by one time of press work, you may divide | segment into several processes and press work.

  Next, the function and effect of the electrode structure 15 will be described. The electrode structure 15 is formed by stacking a plurality of dynodes 10 provided with electron passing holes 11 through which incident electrons pass. And in the peripheral part of each dynode 10, the convex part 23 which protrudes in the lamination direction and the crevice 24 dented in the projection direction of the convex part 23 are provided, and dynodes 10 and 10 mutually adjacent in the lamination direction are The convex part 23 of the dynode 10 on the other side and the concave part 24 of the dynode 10 on the one side are fitted to each other to be positioned. Thus, by providing the convex portion 23 and the concave portion 24 at the peripheral portion of the dynode 10, a structure for stacking can be provided only outside the electron passage hole forming portion EM. A plurality of dynodes 10 can be positioned and stacked without reducing the proportion of the part EM. That is, a plurality of dynodes 10 can be stacked without reducing the effective area of the electron multiplier section 7.

  Moreover, since the insulating layer 23a is provided in the convex part 23 of the other side dynode 10, and the insulating layer 24a is provided in the recessed part 24 of the one side dynode 10, the adjacent dynodes 10 and 10 have insulation. Secured and laminated. From the above, a structure for insulation can be provided only outside the electron passage hole forming portion EM, and the plurality of dynodes 10 are insulated from each other without reducing the proportion of the electron passage hole forming portion EM in the dynode 10. Can be stacked. That is, in the electron multiplying unit 7, a plurality of dynodes 10 can be stacked without reducing the effective region provided with the electron multiplying structure. Furthermore, a plurality of dynodes 10 can be stacked by a simple operation of fitting the concave portions 24 and the convex portions 23 of the adjacent dynodes 10 and 10 together.

  Moreover, since the convex part 23 and the recessed part 24 provided in the dynode 10 are arrange | positioned facing each other along the lamination direction, in the dynode 10, the area | region in which the convex part 23 is provided, and the area | region in which the recessed part 24 is provided Are aggregated. For this reason, for example, when the convex portion 23 and the concave portion 24 are provided on one side of the dynode 10, the convex portion 23 and the concave portion 24 can be formed larger than when the convex portion 23 and the concave portion 24 are provided at different positions. The matching dynodes 10 can be supported more stably.

  Moreover, since the convex part 23 and the recessed part 24 provided in each stage dynode 10 are arrange | positioned along the lamination direction, the fitting part between adjacent dynodes 10 and 10 exhibits a columnar structure as a whole. For this reason, adjacent dynodes 10 and 10 are more firmly fixed.

  Moreover, since the depth of the recessed part 24 is larger than the thickness of the dynode 10, the fitting length of the convex part 23 and the recessed part 24 fitted together becomes large, and adjacent dynodes 10 and 10 are fixed more firmly.

  Here, with reference to FIG. 8, the insulation between the adjacent dynodes 10 will be described. FIG. 8 is a diagram illustrating the IV characteristics of the dynode 10. Graph A1 is a graph showing the IV characteristics in a nitrogen atmosphere, and graph A2 is a graph showing the IV characteristics in an alkali active vacuum. This IV characteristic shows the result of measuring the withstand voltage between the dynodes 10 and 10 by laminating the dynodes 10 treated with the oxalic acid alumite treatment (alumite film thickness: 20 μm). The horizontal axis represents the voltage applied to one dynode 10 and the vertical axis represents the current flowing between the dynodes 10 and 10.

  According to the graph A1, in the nitrogen atmosphere, when the applied voltage was 450 V or less, almost no current flowed (10 pA or less). Further, according to the graph A2, almost no current flowed (less than 10 pA) at an applied voltage of 400 V or less in an alkali active vacuum. As described above, in any case, a high withstand voltage of 300 V or higher was confirmed, and it was confirmed that even with a realistic potential difference between adjacent dynodes 10 and 10, sufficient withstand voltage capability was obtained.

  Thus, the insulating layer 23a and the insulating layer 24a are preferably oxide films of a metal material M such as an insulating alumite film. In this case, since the adhesion of the insulating layer to the dynode 10 is high, the possibility of the insulation structure falling off is suppressed, and the adjacent dynodes 10 and 10 are more reliably insulated.

  The electrode structure according to the present invention is not limited to the one described in this embodiment. For example, as shown in FIG. 9, the dynode 10 may be a multi-channel (for example, 64 channel) dynode electrode in which a plurality of electron passage holes 11 are formed in the row direction and the column direction. Further, the number of stacked dynodes 10 can be set to a desired number.

  As the shape of the dynode 10, various shapes such as a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape (for example, a hexagonal shape and an octagonal shape) can be adopted in plan view. Further, the number and arrangement of the convex portions 23 and the concave portions 24 can be appropriately selected according to the shape of the dynode 10. 10-13 is a figure which shows an example of the number and arrangement | positioning of the convex part 23 and the recessed part 24 with respect to the dynode 10 which has various shapes. 10 to 13, for the sake of convenience, the region including the electron passage hole 11 and the region including the frame portion 21 is referred to as the electrode portion 20, and the region including the protruding portion 22, the protruding portion 23, and the recessed portion 24. Is a fitting portion 25.

  For example, as shown in FIG. 10A, when the electrode part 20 is substantially circular in a plan view, the fitting part 25 is spaced from the peripheral part of the electrode part 20 (for example, at equal intervals). Three or more (three) or more are preferably arranged. Further, as shown in FIG. 10B, when the electrode part 20 has a substantially rectangular shape in plan view, three or more fitting parts 25 are arranged on the side of the electrode part 20 at substantially equal intervals. It is preferable. As described above, when the electrode portion 20 has a strength that does not cause bending or the like, the fitting portion 25 is provided at three or more locations at substantially equal intervals on the peripheral portion of the electrode portion 20, so that the adjacent dynodes 10, 10 are positioned in the x-axis-y-axis-z-axis direction. As a result, a plurality of dynodes 10 can be stacked by a simple operation of fitting the concave portions 24 and the convex portions 23 of the adjacent dynodes 10 and 10 without adjusting their positions.

  Further, as shown in FIG. 11A, when the electrode part 20 is substantially rectangular in a plan view, the fitting part 25 has two places (two on one side or two sides of one side of the electrode part 20). The dynodes 10 and 10 adjacent to each other are positioned in the x-axis-y-axis-z-axis direction. Further, by providing a large number of fitting portions 25, the strength of the electrode portion 20 is supplemented, and the bending of the electrode portion 20 can be suppressed.

  Further, as shown in FIG. 11B, the fitting portion 25 may be provided on the entire peripheral portion of the electrode portion 20. Thus, when there is sufficient space in the peripheral part of the electrode part 20, the adjacent dynodes 10 and 10 are more firmly fixed by providing the fitting part 25 in the whole peripheral part.

  In addition, as shown in FIGS. 12A to 12C, when the electrode part 20 is polygonal in plan view, the fitting part 25 may be provided at a corner part of the electrode part 20. In this case, as shown in FIGS. 12A and 12C, the fitting portion 25 may be provided across two sides forming the corner portion, or (b) in FIG. ), It may be provided so as to be in contact with the corner on one of the two sides forming the corner. In any case, by providing the fitting portion 25 at the corner of the electrode portion 20, the adjacent dynodes 10 and 10 are more stably supported, and the adjacent dynodes 10 and 10 are more reliably separated from each other. The In addition, by arranging the fitting portions 25 at the corners of the electrode portion 20 so as to be rotationally symmetric, adjacent dynodes 10 and 10 are stably supported while the number of fitting portions 25 is suppressed. It becomes possible.

  As shown in FIG. 13, when the electrode portion 20 is polygonal in plan view and the fitting portion 25 is not provided at the corner of the electrode portion 20, the fitting portion 25 is It may be provided on 20 sides. In this case, the electrode part 20 needs to have a strength that does not cause bending or the like.

  Further, as shown in FIGS. 14A and 14B, the protrusion 22 is a portion that substantially protrudes in parallel from the outer peripheral edge of the frame 21 toward the outside in parallel to the frame 21. Only the protruding portion 22 (second portion 22b) that does not have one portion 22a and extends to one side along the z-axis direction is provided on the outer peripheral edge of the frame portion 21, and the protruding portion 22 and the recessed portion 24 are provided on the protruding portion 22. May be provided. At this time, as shown in FIG. 14A, the protruding portion 22 may be provided such that the outer surface of the protruding portion 22 protrudes outward with respect to the outer peripheral edge of the frame portion 21. In this case, since the convex portion 23 and the concave portion 24 are provided outside the outer shape of the frame portion 21 surrounding the electron passage hole forming portion EM, the convex portion 23 and the concave portion 24 are not required to increase the width of the frame portion 21. Is provided stably. For this reason, the convex part 23 and the recessed part 24 are stably provided, without reducing the ratio of the electron passage hole formation part EM in the dynode 10. Furthermore, since the convex part 23 provided with the insulating layer 23a and the concave part 24 provided with the insulating layer 24a are separated from the electron passage hole forming part EM, the incident light is incident on the insulating layer 23a and the insulating layer 24a. It is possible to suppress adverse effects such as defective withstand voltage. Further, as shown in FIG. 14B, the protruding portion 22 may be provided so that the outer peripheral edge of the frame portion 21 and the outer surface of the protruding portion 22 are flush with each other. In this case, since the convex part 23 and the concave part 24 are provided inside the outer shape of the frame part 21 surrounding the electron passage hole forming part EM, the entire dynode 10 can be enlarged. For this reason, the convex part 23 and the concave part 24 are stably provided, without reducing the area of the electron passage hole formation part EM in the dynode 10.

  Further, as shown in FIG. 15A, the protruding portion 22 may be provided so that the other end of the second portion 22b where the concave portion 24 is provided is at the same position as the back surface 10b in the z-axis direction. . In this case, since the processing accuracy of the protruding portion 22 is easily obtained, a more stable fixing structure can be obtained. Further, as shown in FIG. 15B, the protruding portion 22 may be provided so that the other end of the second portion 22b is located on the other side of the back surface 10b. In this case, when the dynode 10 as a component is placed on the placement surface, the main surface 10a and the back surface 10b of the dynode 10 are both separated from the placement surface, so that the placement surface and the electron multiplier piece s are in contact with each other. The deformation of the electron multiplier s due to can be suppressed.

  Various shapes can be adopted as the shape of the convex portion 23 and the concave portion 24. As shown in FIGS. 16A to 16E, the side surface shape along the width direction of the convex portion 23 (periphery direction of the peripheral portion provided with the convex portion 23) is rectangular, streamline shape, A triangular shape, a semicircular shape, a pentagonal shape, or the like can be used. Further, the side surface shape along the width direction of the concave portion 24 (peripheral direction of the peripheral portion where the concave portion 24 is provided) is a rectangular shape, a streamline shape, as shown in FIGS. It can be a triangular shape or the like.

  As shown in FIGS. 16A to 16E, the width of the convex portion 23 and the width of the concave portion 24 are substantially the same and smaller than the width of the second portion 22b, and the length of the convex portion 23 is the concave portion. By making the depth greater than or substantially the same as the depth of 24, the tip and both end faces of the protrusion 23 make point contact or surface contact with the bottom face and both end faces of the recess 24, respectively. For this reason, the convex part 23 is firmly fixed in three directions. As a result, even if the number of the convex portions 23 and the concave portions 24 is small, the adjacent dynodes 10 and 10 are firmly fixed. Further, as shown in FIGS. 16A to 16C, if the side surface shape along the width direction of the convex portion 23 and the side surface shape along the width direction of the concave portion 24 are substantially the same shape. The tip surface and both end surfaces of the convex portion 23 are in surface contact with the bottom surface and both end surfaces of the recess 24, respectively. For this reason, adjacent dynodes 10 and 10 are more firmly fixed.

  Further, as shown in FIGS. 17A to 17D, the convex portion 23 extends along the right end surface 221 in the width direction of the second portion 22b on the right side of the one end portion of the second portion 22b. May be provided in the z-axis direction. In the description of FIG. 17, the words “left” and “right” correspond to “left” and “right” when the second portion 22b is viewed from the front. Moreover, the shape along the width direction of the convex part 23 can be made into rectangular shape, semicircle shape, triangular shape, circular arc shape, etc. In addition, the recess 24 may be provided in the z-axis direction along the right end surface 221 at the other end of the second portion 22b. In this case, since the recessed part 24 is provided along the right end surface 221, the right side is open | released. Moreover, the shape along the width direction of the recessed part 24 can be made into the rectangular shape etc. which have the bottom face 24b and the left end surface 24d, for example. And if the length of the convex part 23 is larger than the depth of the recessed part 24 or substantially the same, the front-end | tip 23t of the convex part 23 will carry out point contact or surface contact with the bottom face 24b of the recessed part 24. Furthermore, if the width of the convex portion 23 and the width of the concave portion 24 are substantially the same, the left end 23 s of the convex portion 23 makes point contact or surface contact with the left end surface 24 d of the concave portion 24. For this reason, the convex part 23 will be fixed in two directions, and in order for adjacent dynodes 10 and 10 to be fixed, the convex part 23 and the recessed part 24 need to be provided with two or more. On the other hand, the shape of the convex part 23 and the shape of the concave part 24 are simple and can be reduced in size compared with the shape shown in FIG. For this reason, it can be used when the space for arranging the convex portion 23 and the concave portion 24 is small.

  Further, as shown in FIGS. 17E and 17F, the convex portion 23 includes a right end surface 23d extending in the z-axis direction along the right end surface 221 of the second portion 22b, and a second end from the right end surface 23d. It is good also as a shape which has the inclined surface 23g inclined toward the left end surface 222 of the part 22b. The inclined surface 23g may be a flat surface as shown in FIG. 17 (e), or may be a curved surface as shown in FIG. 17 (f). The recessed part 24 is good also as a shape which has the inclined surface 24g inclined along the inclined surface 23g of the convex part 23 toward the right end surface 221 from the left end surface 222 of the width direction of the 2nd part 22b. In this case, the inclined surface 23g of the convex portion 23 and the inclined surface 24g of the concave portion 24 are in surface contact with each other. For this reason, the convex part 23 and the recessed part 24 contact each other only by the inclined surfaces 23g and 24g, and the adjacent dynodes 10 and 10 are positioned only by these inclined surfaces 23g and 24g. Therefore, in order for adjacent dynodes 10 and 10 to be fixed, it is necessary to provide a plurality of convex portions 23 and concave portions 24. On the other hand, the shape of the convex part 23 and the shape of the concave part 24 are simple and can be reduced in size compared with the shape shown in FIG. For this reason, it can be used when there is little space where the convex part 23 and the recessed part 24 can be arrange | positioned.

  Thus, the convex part 23 and the recessed part 24 provided in the adjacent dynode 10 can fit the convex part 23 provided in the dynode 10 of the other side, and the concave part 24 provided in the dynode 10 of one side. If present, they need not have the same shape. FIG. 18 is a diagram illustrating an example of a cross section orthogonal to the width direction of the stacked portion of the electron multiplier section 7 according to the modification. As shown in FIG. 18, in the cross section orthogonal to the width direction, the convex portion 23A of the first dynode 10 is rectangular, the convex portion 23B of the second dynode 10 is semicircular, and the third step The convex portion 23C of the dynode 10 of the eye has a triangular shape inclined to the other side from the outside to the inside, and the convex portion 23D of the fourth dynode 10 has a triangular shape inclined to the other side from the inside to the outside. . On the other hand, in the cross section orthogonal to the width direction, the recess 24A of the first stage dynode 10, the recess 24B of the second stage dynode 10, the recess 24C of the third stage dynode 10, and the fourth stage dynode 10 are provided. Each of the recesses 24D has a rectangular shape.

  Thus, of the adjacent dynodes 10 and 10, the convex portion 23 of the dynode 10 on the other side and the concave portion 24 of the dynode 10 on the one side can be fitted, and the convex portion 23 of the dynode 10 on the other side can be fitted. The convex portion 23 and the concave portion 24 of each dynode 10 may have any shape as long as the length is substantially the same as or greater than the depth of the concave portion 24 of the dynode 10 on one side. In this case, when the convex part 23 of the dynode 10 on the other side is fitted into the concave part 24 of the dynode 10 on one side, the tip of the convex part 23 comes into contact with the bottom surface of the concave part 24, so that adjacent dynodes 10, 10 are Spaced apart.

  Moreover, in the said embodiment, although the convex part 23 protrudes to one side along the z-axis direction, the recessed part 24 is dented to one side along the z-axis direction, but the convex part 23 is the other along the z-axis direction. The concave portion 24 may protrude to the other side along the z-axis direction, and the convex portion 23 and the recessed concave portion 24 that protrude along one side in one dynode 10 may protrude along the other side. The convex part 23 and the concave part 24 which are depressed may be mixed. Of the adjacent dynodes 10 and 10, if the convex portion 23 of one dynode 10 and the concave portion 24 of the other dynode 10 are provided at positions facing each other and can be fitted, the convex portion 23 and the concave portion 24 may be provided in any direction along the z-axis direction. When the dynode 10 has only two stages, only the convex portion 23 may be provided on one dynode 10 and only the concave portion 24 may be provided on the other dynode 10.

  The insulating layer 23a and the insulating layer 24a are films that insulate the surface of the metal material M, and can be formed by subjecting the surface of the metal material M to oxidation treatment such as anodizing treatment or thermal oxidation treatment. . For example, when the metal material M is made of aluminum, the insulating layer 23a and the insulating layer 24a can be insulating anodized films formed by anodizing the metal material M. As this alumite treatment, oxalic acid alumite treatment, phosphoric acid alumite treatment, boric acid alumite treatment, sulfuric acid alumite treatment, hydrochloric acid alumite treatment, Keplacoat (KEPLA-COAT: registered trademark) and the like can be used. In addition, the insulating layer 23a and the insulating layer 24a can be films made of an insulating material formed on the surface of the metal material M in addition to the oxide film of the metal material M. For example, the insulating layer 23a and the insulating layer 24a include oxides such as silicon dioxide, iron oxide, copper oxide, chromium oxide, alumina, and magnesium oxide, inorganic polymers (for example, alkoxysilane compounds), insulating resins, and anodic oxide films. It may be an insulating layer formed by evaporating, spraying, plating or applying a layer made of (for example, an alumite film) or polysilazane on the convex portion 23 and the concave portion 24.

  The dynode 10 may employ a configuration including a base B made of an insulating material such as ceramics and a conductive layer 28 disposed on the base B, instead of the configuration made entirely of the metal material M. As shown in FIG. 19, the base B has substantially the same shape as the dynode 10 made of the metal material M. In the base portion B, a plurality of openings are provided in a region at the same position as the region where the electron passage hole forming portion EM is provided in the dynode 10 made of the metal material M. The conductive layer 28 is formed on the region where the plurality of openings are formed in the base B, and the conductive layer 28 is provided with a plurality of openings corresponding to the plurality of openings in the base B. That is, the portion of the dynode 10 where the conductive layer 28 is formed functions as the electron passage hole forming portion EM. The conductive layer 28 is also formed on a region at the same position as the region where the charge supply unit 26 is provided in the dynode 10 made of the metal material M in the base B. That is, the conductive layer 28 formed on the region functions as the charge supply unit 26.

  The conductive layer 28 is a conductive layer formed on the surface of an insulating material, and is made of, for example, a conductive metal such as aluminum, gold, copper, tungsten, nickel, tin, or an alloy thereof. The conductive layer 28 may be made of an oxide conductor such as indium tin oxide (ITO), tin oxide (SnO), or zinc oxide (ZnO), a conductive plastic, a conductive polymer, or the like. In addition, when the dynode 10 is formed from an insulating material, since both the convex part 23 and the recessed part 24 have insulation, the insulating layer 23a and the insulating layer 24a do not need to be provided. As described above, the dynode 10 is configured to have conductivity in the electron passage hole forming part EM and the charge supply part 26 and to have insulation in the convex part 23 and the concave part 24.

  The dynode 10 is molded by a molding method corresponding to the material forming the dynode 10. For example, when the dynode 10 is made of aluminum or an alloy thereof, the dynode 10 is formed by press working, die casting, or cutting. When the dynode 10 is made of silicon, the dynode 10 is formed by dry etching or wet etching. When the dynode 10 is made of ceramics, the dynode 10 is formed by press working, die cutting, lamination (for example, green sheet), powder sintering, stereolithography, or the like. When the dynode 10 is made of machinable ceramics, the dynode 10 is formed by cutting. When the dynode 10 is made of silicon carbide, the dynode 10 is formed by powder sintering.

  When the dynode 10 is made of copper or an alloy thereof, the dynode 10 is formed by pressing, cutting, or lamination (for example, diffusion bonding). When the dynode 10 is made of an alloy containing iron such as stainless steel or iron-nickel, the dynode 10 is molded by pressing, powder sintering, cutting, laser processing, etching, lamination (for example, diffusion bonding) or the like. When the dynode 10 is made of resin, the dynode 10 is molded by molding, cutting, powder molding, injection molding, stereolithography, or the like. When the dynode 10 is made of glass, it is molded by molding, powder sintering, dry etching, wet etching, cutting, laser processing, or the like.

  Next, application examples of the electrode structure according to the present invention will be described. FIG. 20 is a schematic end view of the electron beam excitation light source to which the electrode structure according to the present invention is applied, along the electron incident axis direction. The electron beam excitation light source 30 is a lamp (light source) that excites the scintillator 38 with incident electrons and uses light emitted from the excited scintillator 38. The electron beam excitation light source 30 includes a cylindrical casing 31 made of, for example, glass. One end of the casing 31 is open, and an insulating stem 32 is provided at the one end. In the description of FIG. 20, the stem 32 side along the central axis of the casing 31 is one side, and the other end side of the casing 31 is the other side.

  An insulating electrode support 33 is provided on the stem 32, and a cathode 34, an electron extraction electrode 35, an anode 36, and a scintillator support 37 are stacked on the electrode support 33 in order from one side to the other. ing. The electron extraction electrode 35 is provided with an electron passage hole 35 a at a position corresponding to the central axis of the casing 31, and the anode 36 is provided with an electron passage hole 36 a at a position corresponding to the central axis of the casing 31. Yes. The scintillator support 37 is provided with a scintillator 38 at a position corresponding to the central axis of the housing 31.

  On the peripheral edge of the electrode support 33, a recess 33c that is recessed from the main surface of the electrode support 33 to one side is provided along the stacking direction. A peripheral portion of the cathode 34 is provided with a convex portion 34b extending to one side and a concave portion 34c recessed to the one side from the main surface of the cathode 34 along the stacking direction. A peripheral portion of the electron extraction electrode 35 is provided with a convex portion 35b extending to one side and a concave portion 35c recessed to one side from the main surface of the electron extraction electrode 35 along the stacking direction. On the peripheral edge portion of the anode 36, a convex portion 36b extending to one side and a concave portion 36c recessed to one side from the main surface of the anode 36 are provided along the stacking direction. Since the concave portion 33c, the convex portions 34b, 35b, 36b, and 37b and the concave portions 34c, 35c, and 36c are the same as the concave portion 17, the convex portion 23, and the concave portion 24 provided in the photomultiplier tube 1, respectively, description thereof is omitted. .

  The electrode support base 33 and the cathode 34 are stacked on each other by fitting the convex part 34 b of the cathode 34 into the concave part 33 c of the electrode support base 33. The cathode 34 and the electron extraction electrode 35 are stacked on each other by fitting the convex portion 35 b of the electron extraction electrode 35 into the concave portion 34 c of the cathode 34. The electron extraction electrode 35 and the anode 36 are stacked on each other by fitting the convex portion 36 b of the anode 36 into the concave portion 35 c of the electron extraction electrode 35. The anode 36 and the scintillator support base 37 are stacked on each other by fitting the convex part 37 b of the scintillator support base 37 into the concave part 36 c of the anode 36. As a result, the electrode structure 15A is formed.

  FIG. 21 is a schematic end view along the electron incident axis direction, in which only the electron gun portion of an X-ray tube to which the electrode structure according to the present invention is applied is extracted. The electron gun unit 40 is a device that emits electrons by heating a cathode in a high vacuum tube. As shown in FIG. 21, the electron gun unit 40 includes a container (electron gun housing case) 41 whose central axis is arranged substantially parallel to the electron incident axis, and is held in the container 41 by a stem pin 46. The electrode structure 15B (electron gun) is accommodated. The electrode structure 15 </ b> B includes a heater 42 that generates heat when power is supplied from the outside, a cathode 43 that is heated by the heater 42 and emits electrons, a cathode support portion 44 that supports the cathode 43, and is emitted from the cathode 43. A plurality of focus grid electrodes 45 that focus the electrons are stacked. The focus grid electrode 45 is made of a conductive material, and an electron passage hole 45a through which electrons pass is provided at substantially the center thereof. The container 41 is provided with an electron passage hole 41 a for emitting electrons focused by the focus grid electrode 45. In the description of FIG. 21, along the central axis of the container 41, the side on which the heater 42 is provided is one side, and the side on which the electron passage hole 41a is provided is the other side.

  A concave portion 44 c that is recessed toward one side from the main surface of the cathode support portion 44 along the electron incident axis direction is provided at the peripheral edge portion of the cathode support portion 44. On the periphery of the focus grid electrode 45, a convex portion 45b extending to one side and a concave portion 45c recessed to the one side from the main surface are provided along the electron incident axis direction. Since the concave portion 44c, the convex portion 45b, and the concave portion 45c are the same as the concave portion 17, the convex portion 23, and the concave portion 24 provided in the photomultiplier tube 1, description thereof is omitted. The adjacent focus grid electrodes 45 and 45 are stacked on each other by fitting the convex portion 45 b of one focus grid electrode 45 into the concave portion 45 c of the other focus grid electrode 45. Similarly, the cathode support portion 44 and the focus grid electrode 45 disposed on the most side are stacked on each other by fitting the convex portion 45b of the focus grid electrode 45 into the concave portion 44c of the cathode support portion 44. As a result, the electrode structure 15B is formed.

  As described above, the electrode structure according to the present invention includes a charged particle detector such as a photomultiplier tube, a photoelectric tube, and an electron multiplier, as well as a charged electron emission source (electron gun) such as an electron beam excitation light source and an X-ray tube. ) Can be applied to an apparatus having an electrode structure in which electrodes provided with openings through which charged particles pass are stacked in a plurality of stages.

  DESCRIPTION OF SYMBOLS 10 ... Dynode (electrode), 11, 35a, 36a, 45a ... Electron passage hole (opening), 15, 15A, 15B ... Electrode structure, 23, 34b, 35b, 36b, 45b ... Convex part, 23a ... Insulating layer, 24, 34c, 35c, 36c, 45c ... concave portion, 24a ... insulating layer, 27 ... raised portion, 28 ... conductive layer, 34 ... cathode (electrode), 35 ... electron extraction electrode (electrode), 36 ... anode (electrode), 45: Focus grid electrode (electrode), EM: Electron passage hole forming part (opening forming part).

Claims (18)

An electrode structure formed by laminating a plurality of electrodes provided with openings through which charged particles pass,
The plurality of electrodes include first and second electrodes that are provided with the opening and have an opening forming portion having conductivity, and are adjacent to each other in the stacking direction,
On the outer peripheral edge of the peripheral edge portion of the first electrode, a convex portion protruding in the stacking direction is provided,
The outer peripheral edge of the peripheral edge of the second electrode is provided with a concave portion that is recessed in the direction in which the convex portion protrudes,
The first and second electrodes are positioned to each other by fitting the convex portion provided in the first electrode and the concave portion provided in the second electrode,
At least one of the convex portion provided on the first electrode and the concave portion provided on the second electrode has an insulating property, and the first and second electrodes are insulated from each other. An electrode structure characterized by that.   The electrode structure according to claim 1, wherein the convex portion and the concave portion have insulating properties. The plurality of electrodes are made of a conductive material,
The electrode structure according to claim 1, wherein an insulating layer is provided on at least one of the convex portion and the concave portion. The conductive material is a metal material,
The electrode structure according to claim 3, wherein the insulating layer is made of a film that insulates the surface of the metal material.   The electrode structure according to claim 4, wherein the film is an oxide film obtained by oxidizing the surface of the metal material. The plurality of electrodes further includes a base portion made of an insulating material and provided with an opening corresponding to a position where the opening is provided,
The electrode structure according to claim 1, wherein the opening forming portion is made of a conductive layer disposed on the base portion. The base includes the peripheral edge;
The electrode structure according to claim 6, wherein the convex portion and the concave portion are provided in the base portion.   The depth of the said recessed part is larger than the thickness of the said electrode in which the said recessed part was provided, The electrode structure as described in any one of Claims 1-7 characterized by the above-mentioned.   9. The electrode structure according to claim 1, wherein a length of the convex portion in the stacking direction is equal to or greater than a depth of the concave portion fitted into the convex portion. . Each of the plurality of electrodes is provided with a convex portion projecting in the stacking direction and a concave portion recessed in the direction in which the convex portion projects, on the outer peripheral edge of the peripheral portion,
The electrode structure according to claim 1, wherein the convex portion and the concave portion are arranged to face each other in the stacking direction.   The electrode structure according to claim 10, wherein the convex portion and the concave portion are arranged along the stacking direction. The said convex part and the said recessed part are respectively provided with three or more at intervals in the outer periphery of the said peripheral part of the said electrode, The Claim 1 characterized by the above-mentioned. Electrode structure. The plurality of electrodes are polygons in plan view,
The said convex part and the said recessed part are respectively provided in one or more sides of the said electrode, and one or more are provided in the edge | side facing the said one side, The any one of Claims 1-11 characterized by the above-mentioned. The electrode structure according to claim 1. 12. The electrode structure according to claim 1, wherein each of the convex portion and the concave portion is provided over the entire outer peripheral edge of the peripheral edge portion. The plurality of electrodes are polygons in plan view,
The convex part is located at a corner of the electrode provided with the convex part,
The said recessed part is located in the corner | angular part of the said electrode in which the said recessed part was provided, The electrode structure as described in any one of Claims 1-11 characterized by the above-mentioned. The convex portion is provided along the peripheral edge portion of the electrode provided with the convex portion,
The recess is provided along the peripheral edge of the electrode provided with the recess;
The projecting portion and the recessed portion to be fitted are in contact with each other in three directions: a direction in which the projecting portion protrudes and both directions along the peripheral edge portion where the projecting portion is provided. The electrode structure according to claim 15. The convex portion is provided along the peripheral edge portion of the electrode provided with the convex portion,
The recess is provided along the peripheral edge of the electrode provided with the recess;
The convex portion and the concave portion to be fitted are in contact with each other in two directions , that is, a direction in which the convex portion protrudes and one of the two directions along the peripheral edge portion where the convex portion is provided. The electrode structure as described in any one of Claims 1-15 characterized by the above-mentioned. The plurality of electrodes further includes a third electrode adjacent to the second electrode,
On the outer peripheral edge of the peripheral edge portion of the second electrode, a convex portion that protrudes in the direction in which the concave portion is recessed is further provided,
On the outer peripheral edge of the peripheral portion of the third electrode, a concave portion is provided that is recessed in a direction in which the convex portion provided on the second electrode protrudes,
The second and third electrodes are positioned with each other by fitting the convex portion provided on the second electrode and the concave portion provided on the third electrode,
At least one of the convex portion provided on the second electrode and the concave portion provided on the third electrode has an insulating property, and the second and third electrodes are insulated from each other. The electrode structure as described in any one of Claims 1-17 characterized by the above-mentioned.

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