JP2628183B2 - Photomultiplier tube - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photomultiplier tube having an insulating support provided with a hole for mounting a dynode and an anode electrode.

[Prior Art] In a photomultiplier tube, a pair of insulating supports for supporting a plurality of dynodes and an anode electrode are arranged to face each other.

FIG. 10 shows JP-A-57-124843, JP-A-60-254547,
1 is an exploded perspective view showing an example of a pair of insulating supports 70 and 71 and an electrode 72 such as a dynode as disclosed in Japanese Patent Application Laid-Open No. 60-244548.

As shown in FIG. 10, the electrode 72 is a hole in the insulating support 70.
It has legs 73 and 74 that are fitted to 75 and 76 to position and hold the electrode 72 at a predetermined position. The holes 75 and 76 of the insulating support 70 are conventionally formed at the bases of the legs 73 and 74 of the electrode 72.
Leg 7 with the same shape (eg rectangular) as the cross-sectional shape of 77,78
It had the same cross-sectional area along the 3,74 insertion direction, and its cross-sectional area was only slightly larger than the cross-sectional area of the bases 77,78.

[Problems to be solved by the invention]

Therefore, there is a problem that the legs 73, 74 cannot be inserted into the holes 75, 76 unless the legs 73, 74 of the electrode 72 are accurately aligned with the holes 75, 76. That is, the legs 73, 74 have holes 75,
If it is slightly offset from 76, legs 73 and 74
When inserted into holes 75 and 76, legs 73 and 74 may be bent.
There is a problem that it is not possible to insert into the device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photomultiplier tube having an insulating support provided with a hole through which a leg of an electrode can be easily inserted and the leg can be firmly supported.

[Means for solving the problem]

The present invention provides a photomultiplier tube provided with an insulating support having a hole for inserting a leg portion of an electrode, wherein the hole is
According to the prior art, a photomultiplier tube having a support hole for positioning an electrode at a predetermined position and an introduction hole for guiding a leg of the electrode to the position of the support hole is provided. It is to improve the problem. The hole may have a taper on the insertion side of the leg of the electrode.

[Action]

According to the present invention, when the leg of an electrode such as a dynode is inserted into the hole of the insulating support, and is supported by the supporting hole of the hole to position the electrode in a predetermined position, the leg of the electrode is first supported. Even if it is at a position shifted from the position of the hole, if it is located at the introduction hole of the hole, by pushing the electrode toward the hole, the leg of the electrode will move over the introduction hole to the position of the support hole. It moves and is aligned with the support hole. By further pressing the electrode, the leg is inserted into the support hole and is supported by the support hole. By tapering the side of the hole into which the leg is inserted, the leg can be smoothly moved in the introduction hole, and the leg can be smoothly inserted into the support hole.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partially cutaway sectional view of one embodiment of a photomultiplier according to the present invention. The photomultiplier tube 1 includes an envelope 4 having a cylindrical side wall 2 and a face plate 3. The inner wall portion 5 of the side wall 2 adjacent to the face plate 3 is provided with an aluminum coating. A photocathode 6 is provided along the inner wall of the face plate 3 and a part of the inner wall portion 5 of the side wall on which the aluminum coating is applied.
For the photocathode 6, a photoelectron emitting material such as potassium antimonide and cesium can be used.

In the envelope 4, a flange-shaped electric field forming electrode 7 is provided at a distance from the photocathode 6, and the electric field forming electrode 7 is provided with a pair of insulating supports 8 provided opposite to each other. Supported by nine. The insulating supports 8 and 9 are made of, for example, alumina. In the envelope 4, an electron multiplier 10 is provided for multiplying photoelectrons emitted from the photocathode 6 and extracting the photoelectrons as a current. Electron multiplier 10
Is composed of a plurality of dynodes 11 to 18 and an anode electrode 19. Each of the dynodes 11 to 18 is formed of a material such as an alkali antimonide and a beryllium copper alloy. The electron multiplier 10 has a box-and-grid structure in FIG.

FIG. 2 is an exploded schematic perspective view of an insulating support, dynodes, and anode electrodes. However, for simplicity, only one insulating support 8 and dynode 11 are shown in FIG. In FIG. 2, holes 20 to 27 corresponding to a plurality of dynodes 11 to 18 and holes 28 corresponding to the anode electrode 19 are formed at predetermined positions in the insulating support 8. A similar hole is formed in the other insulating support 9. The dynode 11 has legs 29, 30 at both ends, the legs 29, 30 have a substantially constant thickness, and the tip is, for example, an arc. Other dynodes 12-18,
The anode electrode 19 also has similar legs, not shown.

The leg of each electrode is a part of an electrode that holds the electrode by being fitted into each of the holes 20 to 28 of the insulator support 8. Each of the holes 20 to 28 of the insulating support 8 has a dynode 11 to 1
8, the legs of the anode electrode 19 are inserted respectively.

FIG. 3 (a) is a plan view of the hole of the first embodiment, FIG. 3 (b) is a sectional view taken along line AA of FIG. 3 (a), and FIG.
FIG. 3C is a sectional view taken along line BB in FIG. 3A. In the hole of the first embodiment, when inserting the electrode legs 29 and 30 as shown in FIG. 2, the cylindrical introduction hole 34 for guiding the electrode legs 29 and 30 and the insertion of the electrode legs are completed. Slit-shaped support hole that matches the cross-sectional shape of the leg at the position and at both ends
35,36. The introduction hole 34 and the support holes 35, 36 are formed integrally, and these joints 37 have a predetermined radius of curvature and smoothly join the introduction hole 34 and the support holes 35, 36. I have. In addition, the introduction hole 34, the support holes 35, 36, and the joint 37
Are provided with a taper 38 of uniform width and depth, respectively. The dimensions of the holes, that is, the width W of the support holes 35 and 36, the total length L of the holes, the diameter D of the introduction hole 34, the width t of the taper 37, and the depth H of the taper 37 are determined by the dyed nodes 11 to 18 and the anode electrode. Determined by the shape of each of the 19 legs. The width W of the support holes 35 and 36 is determined by the thickness of the leg of the electrode, for example, about 0.45
Set to mm. The width t and depth H of the taper are, for example, about
It is set to 0.2mm. The total length L of the hole is determined by the width of the electrode leg, for example, about 9.1 mm, about 5.1 mm, about 4.1 mm, about 3.0 m
m, and the diameter D of the introduction hole 34 is set to about 4.0 mm, about 3.0 mm, about 2.5 mm, and about 1.5 mm, respectively, corresponding to each value of the total length L. The thickness P of the insulating supports 8 and 9 is about 1.5 mm.
It has become about.

An operation for introducing the electrode leg into the hole having such a configuration will be described. In the case where the tip of the electrode leg 40 has an arc shape like the legs 29 and 30 shown in FIG. As shown in the figure, even when the leg 40 is initially displaced from the slit-shaped support holes 35 and 36 (shown by broken lines), the tip of the leg 40 is located in the introduction hole 34. Then, by pushing the leg 40 toward the hole, the tip of the leg 40 slides in the direction shown by the arrow F and is guided to the positions of the slit-like support holes 35 and 36. As a result, the leg 40 can be aligned with the support holes 35 and 36. By further pushing the leg 40, the leg 40 is inserted into the support holes 35 and 36 to support the leg 40. The holes 35 and 36 can be firmly supported. The electrode tab 40 can be smoothly slid by the taper 38 provided around the hole, and the electrode leg 40 can be easily guided to the positions of the support holes 35 and 36.

FIG. 5 is a plan view of a hole according to the second embodiment. The hole of the second embodiment is a joint 3 between the support holes 35, 36 and the introduction hole 34.
The width t 'of the taper 38' at 7 'is wide (for example, about 0.4mm)
Has become. As a result, the legs of the electrode can be guided and inserted into the support holes 35 and 36 more smoothly than the holes of the first embodiment.

FIGS. 6 and 7 are plan views of the holes of the third and fourth embodiments, respectively. In the third embodiment, the cross-sectional shape of the introduction hole 41 is rhombic, and in the fourth embodiment, the introduction hole is formed.
The cross-sectional shape of 42 is almost rectangular. In this manner, the cross-sectional shape of the introduction hole can be not only circular but also rhombic, rectangular, or the like, and the cross-sectional shape of the introduction hole can be any shape suitable for the shape of the tip of the leg of the electrode. It can be shaped. Furthermore, according to the shape of the legs, support holes,
The shape of the introduction hole can be determined. For example, in FIG. 8, when the leg 51 of the dynode 50 is L-shaped,
52 and 53 can be positioned at right angles to each other, and the cross-sectional shape of the introduction hole 54 can be semicircular.

FIG. 9 (a) is a plan view of a hole in the fifth embodiment, and FIG. 9 (b) is a cross-sectional view taken along line CC in FIG. 9 (a). In the hole of this embodiment, the width of the taper 45 of the introduction hole 44 is wide, and the minimum width M of the introduction hole 44 is
It is the same as the minimum of 5,36. Thereby, the leg portion of the electrode can be reliably supported by the insulating support.

In this manner, by using the insulating support having the holes of the present embodiment (for example, the first embodiment), the time for assembling the electrodes by the same operator can be reduced by about 1/2 compared to the related art. I was able to.

In each of the above embodiments, the tapered surface is a flat surface, but may be a curved surface having a predetermined radius of curvature. Further, in the above-described embodiment, the taper is formed on both sides of the holes of the insulator supports 8, 9, because the legs of the electrodes can be easily inserted into the holes from either side, If the leg is inserted from any one side of the hole, the condition is not necessarily required for the present invention, and only the side to be inserted need be tapered.

〔The invention's effect〕

As described above, according to the present invention, since the introduction hole for guiding the leg of the electrode to the position of the support hole is provided in the hole, the leg of the electrode is easily aligned with the hole and inserted. As a result, the support hole can be firmly supported. If a taper is provided on the leg insertion side of the hole, the leg can be more easily positioned and inserted.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view of one embodiment of a photomultiplier according to the present invention, FIG. 2 is an exploded perspective view of an insulating support and electrodes to be attached to the insulating support, and FIG. a) is the first
3 (b) is a cross-sectional view taken along line AA of FIG. 3 (a), and FIG. 3 (c) is FIG. 3 (a).
FIG. 4 is a cross-sectional view taken along the line BB of FIG. 4, FIG. 4 is a view for explaining the operation of introducing the leg of the electrode into the hole of FIGS. 3 (a) to 3 (c), and FIG. FIG.
FIG. 7 is a plan view of the holes of the third and fourth embodiments, respectively.
FIG. 8 is a view showing the configuration of a hole when the leg portion of the electrode has an L-shape, FIG. 9 (a) is a plan view of the hole of the fifth embodiment, and FIG. 9 (b) is FIG. 9 (a) is a sectional view taken along the line CC, and FIG. 10 is an exploded perspective view of a conventional insulating support and electrodes to be attached to the insulating support. 8, 9 ... insulating support, 10 ... electron multiplier, 11 to 18 ... dynode, 19 ... anode electrode, 20 to 28 ... hole, 29, 30, 40, 51 ... electrode legs Part, 34,41,42,44,54 …… Introduction hole part, 35,36,52,53 …… Support hole part, 37,43 …… Connection part, 38,38 ', 45 …… Taper

Claims (2)

(57) [Claims] 1. A photomultiplier tube provided with an insulating support having a hole for inserting a leg of an electrode, wherein the hole comprises:
A photomultiplier tube comprising: a support hole for positioning a predetermined electrode at a predetermined position; and an introduction hole for guiding a leg of the electrode to the position of the support hole. 2. The photomultiplier tube according to claim 1, wherein said hole has a taper on the side where the leg of the electrode is inserted.