JPH06314600A - Ion accelerating electrode plate and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide an ion accelerating electrode plate having a cooling passage that can cool portions near a beam hole having high cooling performance, and excellent in durability and corrosion resistance, and a method of manufacture thereof. CONSTITUTION:A flat tantalum plate 2 is laid via titanium foil 4 on top of a grooved tantalum plate 1 having a number of grooves 3 formed thereon, and the plates are joined together by diffusion process. A beam hole 5 is bored along the direction perpendicular to the surface of this electrode plate and in the adjoining position of cooling holes. An excellent joint is thus formed without deforming the grooves that serve as the cooling holes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion accelerating electrode plate having a high cooling performance in an ion source used for a neutral particle injection device, an active particle beam injection device, etc. of a nuclear fusion device, and a manufacturing method thereof.

[0002]

2. Description of the Related Art A neutral particle injection device for a fusion device is a device for injecting a high-energy neutral particle beam into the plasma in the fusion device from the outside and heating it. The ion source, which is the source of this neutral particle beam, generates plasma by performing arc discharge in hydrogen gas, and accelerates the ions in it by the electrode to which a high voltage is applied. This hydrogen ion beam has electrons attached to it and is neutralized to become an incident beam. (Reference, present state of fusion research and development, published by Japan Atomic Energy Research Institute in 1985) The electrode plate that accelerates the ion beam is made of molybdenum, which has a high melting point, and passes ions as shown in FIGS. 3 and 4. The structure is provided with an infinite number of beam holes 5.
Incidentally, a part of the beam hole 5 in FIG. 4 is indicated by the center line. Further, in order to prevent overheat damage due to collision of an ion beam or the like, a structure in which a copper pipe 7 is brazed with a brazing material 8 around a molybdenum flat plate 6 and water-cooled is used.
The ion acceleration electrode plate of the active particle beam injector for measuring the temperature of the central part of the plasma has the same structure.

[0003]

In recent years, as the performance of the neutral particle injection device and the like has been improved, higher output of the ion source and longer pulse of the beam output time have been required, and the ion acceleration electrode plate has been demanded. Durability is a problem. By increasing the pulse length and increasing the output, the heating load on the molybdenum flat plate increases, so in the conventional structure where the surroundings are cooled,
The cooling effect is insufficient and a high cooling performance structure is required to directly cool the periphery of the beam hole.

However, since the space between the beam holes is narrow and only a width of 1 to 2 mm is allowed to provide the cooling water channel, it is difficult to mount the water cooling copper pipe on the surface. Further, when such a water channel is brazed by a pipe or the like, an element having a high vapor pressure contained in the brazing material evaporates during heating, and the degree of vacuum in the apparatus is deteriorated.

Further, molybdenum is easily oxidized and changes its color to blue when left in a humid atmosphere, and is easily oxidized. Even if a cooling hole is provided so as to directly cool the periphery of the beam hole, it is directly When it comes into contact with cooling water, there is a problem that it is oxidized and corrodes when used for a long time and penetrates the adjacent beam hole.

Further, even if the surface of the cooling hole can be coated with a material having corrosion resistance, there is a problem in that long-term reliability is not achieved with a thickness of several microns. Further, when the electrode plate is made of copper which is excellent in water corrosion resistance, the melting point is low, which causes problems such as damage and thermal deformation due to the heat load of the beam.

An object of the present invention is to provide an ion accelerating electrode plate having a cooling path capable of arbitrarily cooling the vicinity of the beam hole, having high cooling performance, excellent durability and corrosion resistance, and a method for manufacturing the same.

[0008]

According to a first aspect of the present invention, a large number of beam holes for passing an ion beam are provided in a direction intersecting the surface of the beam, and a high voltage is applied to accelerate the ion beam passing through the beam hole. In the ion accelerating electrode plate, it has a polymer plate structure integrated by diffusion bonding of a tantalum plate, and is provided with cooling holes for cooling water circulation consisting of a tubular space adjacent to the beam hole in an arrangement along the polymerizing surface. And an ion accelerating electrode plate.

A second aspect of the invention is to form a grooved tantalum plate by covering the groove on a grooved tantalum plate having a large number of grooves formed on one side and stacking a tantalum thick plate through titanium to perform diffusion bonding. And a tantalum flat plate are integrally fixed to each other, and then beam hole processing is performed, which is a method of manufacturing an ion acceleration electrode plate.

[0010]

According to the first aspect of the present invention, the tantalum plate has a polymerized structure integrated by diffusion bonding, and has a cooling hole for cooling water circulation formed of a tubular space adjacent to the beam hole in an arrangement along the polymerized surface. Therefore, the cooling performance of the tantalum plate is good. Further, since the joined portion of the tantalum plate is integrated by diffusion joining, the airtightness is maintained, and unlike brazing, there is no problem of degrading the degree of vacuum in the apparatus due to evaporation of the brazing material.

Moreover, since tantalum has a high melting point of about 3000 ° C., it is effective in preventing damage due to the beam heat load, and has excellent corrosion resistance to cooling water, so that it is possible to increase durability.

In the second aspect of the invention, since the groove closed by the superposition of the grooved tantalum plate and the flat plate tantalum is used as the cooling hole, the cooling hole may be formed unlike the conventional pipe structure. Is easy to process,
The arrangement and size can be arbitrarily selected.

Therefore, it is possible to easily form a cooling hole having a small diameter even in a narrow gap between the beam holes. Also, in the diffusion bonding of the grooved tantalum plate and the flat plate tantalum plate,
Since joining is performed via titanium, it is possible to form a joined portion with excellent airtightness and joining strength, even if the joining temperature and the pressure applied during joining are reduced, as compared with the case of directly joining the tantalum plates by diffusion joining. .

Furthermore, since the joining temperature and the pressure applied at the time of joining are low, it is possible to prevent the grooves forming the cooling holes from being deformed, and it is possible to form the cooling holes having a predetermined size even after the joining. It will be possible.

Further, since titanium is softer than tantalum at high temperature, the plastic deformation of titanium during joining makes it easy to adapt to the irregularities of the machined surface of tantalum, and the airtightness without defects on the normal machined surface roughness. There is an advantage that a high joint can be obtained.

[0016]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. In this embodiment, as shown in FIG. 1A, a flat tantalum plate 2 is superposed on a grooved tantalum plate 1 having a large number of grooves 3 formed on one side thereof via a titanium foil 4 having a thickness of 10 μm. Was diffusion-bonded to form a single tantalum plate as an electrode plate spare part. After this
As shown in (b) and FIG. 2, a large number of beam holes 5 were formed at positions adjacent to the cooling holes 3a along the direction intersecting the surface of the electrode plate spare part.

The groove size of the above-mentioned spare electrode plate is 1.5
mm, and the depth dimension was 1 mm. Furthermore, flat tantalum plate 2
Has a thickness of 0.5 mm, the grooved tantalum plate 1 has a thickness of 1.5 mm, and both have a diameter of 340 mm.

Diffusion bonding between the grooved tantalum plate 1 and the flat plate tantalum plate 2 is performed by using a hot press machine, the bonding temperature is 1000 ° C., the holding time is 1 Hr, and the bonding surface pressure is 1.0 kg.
f / mm ² and the degree of vacuum are 5 × 10 ^-5 Torr.

FIGS. 1 (b) and 2 show an electrode plate as a final product in which a beam hole 5 is formed in the electrode plate spare part having the above-mentioned structure. That is, 450 beam holes 5 having a diameter of 6 to 8 mm were drilled by machining on the tantalum plate integrated as described above. In this case, the distance between the periphery of the beam hole 5 and the closest cooling hole 3a was 0.4 mm.

According to the ion accelerating electrode plate of this embodiment, the tantalum plate has a superposed structure of the grooved tantalum plate 1 and the flat plate tantalum plate 2, and the groove 3 closed by the joining thereof becomes the cooling hole 3a. Therefore, since the cooling holes 3a may be formed by grooves, it is relatively easy to process, and the arrangement and size thereof can be arbitrarily selected, and the cooling holes 3a can be close to a narrow gap between the beam holes 5. The cooling holes 3a can be arranged, and the cooling efficiency can be improved.

Further, since the diffusion bonding of the grooved tantalum plate 1 and the flat plate tantalum plate 2 is performed through the titanium 4, the bonding temperature in the case of direct bonding is 1300 ° C. and the surface pressure is 1 to 2.0 kgf / mm ^2.
It was possible to carry out at a temperature sufficiently lower than that of, and it was possible to secure the designed cooling water flow rate without the problem of groove deformation during joining. In addition, the processing accuracy of the joint surface can be achieved with the normal 6S. The adhesion strength of these diffusion joints is much higher than the water pressure of the cooling water. Moreover, the airtightness is determined by the cooling holes 3.
In a helium leak test in which a was a vacuum and helium gas was blown from the outside, it was confirmed that the airtightness was sufficient at 1 × 10 ⁻⁹ Torr · l / sec or less. Further, titanium can be applied by vapor deposition or ion plating in addition to the foil.

Furthermore, since this electrode plate is made of tantalum, it does not show discoloration or corrosion due to oxidation unlike the conventional molybdenum in the long-term water-cooling test and the immersion test in cooling water, and it has excellent water-corrosion resistance. Was also confirmed. Therefore, according to the ion accelerating electrode plate of the present embodiment, excellent cooling performance can be obtained with high reliability over a long period of time, and it is possible to achieve higher functionality and longer life.

[0023]

As described above, according to the ion accelerating electrode plate of the present invention, the tantalum plate has a polymer plate structure integrated by diffusion bonding, and the cooling hole adjacent to the beam hole is arranged. Is excellent. In addition, since it is diffusion-bonded through titanium, it is possible to provide a bonded portion having high adhesion and airtightness without deforming the groove serving as the cooling hole. Furthermore, since the electrode plate is made of tantalum, it not only excels in heat resistance but also in water corrosion resistance.
It is possible to secure the cooling performance for a long period of time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a process of manufacturing an ion accelerating electrode plate according to the present invention and a completed product.

FIG. 2 is a plan view of the ion acceleration electrode plate shown in FIG.

FIG. 3 is a plan view showing a conventional ion acceleration electrode plate.

4 is a sectional view of the ion acceleration electrode plate shown in FIG.

[Explanation of symbols]

 1 Tantalum plate with groove 2 Tantalum flat plate 3 Cooling groove 4 Titanium foil 5 Beam hole 3a Cooling hole

Claims (2)

[Claims] 1. An ion accelerating electrode plate having a large number of beam holes for passing an ion beam in a direction intersecting the surface thereof and accelerating the ion beam passing through the beam holes by applying a high voltage. An ion accelerating electrode plate having a structure of a superposed plate integrated by diffusion bonding and having a cooling hole for cooling water flow, the cooling hole having a tubular space adjacent to the beam hole and arranged along the superposed surface. 2. A tantalum plate with grooves and a tantalum flat plate are integrated by stacking a tantalum thick plate over the grooves on a tantalum plate with grooves having a large number of grooves formed on one side thereof through titanium and performing diffusion bonding. A method for manufacturing an ion accelerating electrode plate, which comprises: fixing and fixing, and then performing beam hole processing.