JP2011076937A - Electrode for ion source - Google Patents

Abstract

A long-life ion source electrode having high cooling efficiency and excellent corrosion resistance is provided.
A pair of heat-resistant electrode plates 1, 1A, 1B made of a heat-resistant metal material having a plurality of beam holes 23 for extracting an ion beam and at least one of which has continuous grooves 2, 2A, 2B. , 3, 3A, 3B and a pair of heat-resistant electrode plates, and are tightly bonded to each of the heat-resistant electrode plates so as to cover the peripheral wall of the groove, and are made of a corrosion-resistant metal material. 4B, 5, 5A, 5B, and the vicinity of the beam hole, the periphery is defined by a barrier material that covers the peripheral wall of the groove, the coolant for cooling the heat-resistant electrode plate flows, at least a part of the groove And refrigerant passages 22, 22A, 22B disposed so as to enter 2, 2A, 2B.
[Selection] Figure 3

Description

  The present invention relates to an ion source electrode for generating a high-speed ion beam by accelerating ions in plasma in an ion source applied to a neutral particle injection device, an ion mixing device, or the like of a fusion apparatus.

  An ion source that generates a fast ion beam from plasma is used in a neutral particle injection device or ion mixing device of a fusion device. For example, in an ion source of a neutral particle injection device used in a nuclear fusion device, a plasma such as hydrogen is introduced into a plasma generation unit and arc discharge is performed through a filament to generate plasma. The ions ionized by the gas in the plasma are extracted from the plasma and accelerated by an electric field formed by applying a high voltage to a plurality of electrodes. In this way, a high-speed ion beam having high energy is generated. Since the ion beam is bent by the magnetic field of the coil of the fusion device as it is, it is passed through the neutralization cell filled with gas, and the kinetic energy is preserved by the collision reaction between the ion and gas, and the neutral beam is converted. Convert and enter the core plasma.

  The plurality of ions for accelerating ions in the ion source described above are configured by three or five stages of electrodes spaced apart in parallel. A number of ion beam extraction holes are formed in each electrode so as to extract the ion beam from the plasma. In particular, the first electrode closest to the ion source has a structure in direct contact with a high-temperature ion beam. For this reason, the electrode is formed with a cooling channel that lowers the thermal load of the electrode itself and improves the durability. Usually, the cooling channel is provided between a plurality of ion beam extraction holes formed in order to effectively perform cooling.

  As shown in FIG. 24, the conventional ion source electrode 200 has a large number of beam extraction holes 223 formed through electrode plates 201 and 203 made of molybdenum, which have high heat resistance, low linear expansion coefficient, and excellent availability. It has. Cooling channels 222 through which a coolant flows are formed on both sides of the beam extraction hole 223 to cool the Mo electrode plates 201 and 203 that are heated by ion beam radiation.

  More specifically, of the two Mo electrode plates 201 and 203, a grooved flat plate having a cooling channel 222 is used for one plate 203, and a flat plate is used for the other plate 201. A sheet of molybdenum plates 201 and 203 is diffusion bonded using a hot press apparatus capable of pressing at high temperature in vacuum, and a plurality of beam extraction holes 223 penetrating the Mo electrode plates 201 and 203 are formed. It is.

  By the way, when an ion beam is extracted using the ion source electrode having the above-described configuration, pure water as a coolant is put into the cooling channel 222 in order to reduce the heat load of the ion source electrode itself. Pass through. In general, molybdenum is used as a material for the electrode plates 201 and 203 because it has a high thermal load, and a material with a small coefficient of linear expansion to maintain the accuracy of the position of the beam extraction hole 223 due to thermal load. Although used, this molybdenum plate is made of sintered metal, and therefore has a drawback of corroding with cooling water such as pure water. According to the experience of the present inventors, it has been found that the usable life as the electrode is as short as 1 to 2 years. For these reasons, there is a demand for an ion source electrode that is resistant to corrosion and has excellent corrosion resistance and a long lifetime.

  Therefore, as a countermeasure, Patent Document 1 proposes a method for manufacturing an ion source electrode. That is, in this method, the groove surface of the grooved molybdenum plate provided with the groove for the cooling water passage is coated with nickel to prevent corrosion due to cooling water, and a molybdenum plate coated with nickel is stacked thereon, In addition to being integrated with the grooved molybdenum plate by diffusion bonding, a cooling water passage hole covered with nickel is formed, and then the ion beam hole is processed. In particular, this electrode is mounted on the opening side of the plasma generation unit and is made of molybdenum, which is a refractory metal and a high melting point material suitable for an electrode for forming an electric field.

  In the structure described in Patent Document 2, molybdenum is coated with nickel as in Patent Document 1 described above, but brazing is used for this joining. In the structure of Patent Document 2, the barrier layer has a groove, and the heat-resistant material has no groove.

  Similar to the above-mentioned publication, in the structure described in Patent Publication 3, in the electrode for an ion source mainly composed of a molybdenum plate, the molybdenum plate has a superposed plate structure integrated by diffusion bonding, and for the cooling water passage. An electrode for an ion source in which the inner peripheral surface of the cooling hole is coated with a ceramic coating layer, and in this case, a method of forming the ceramic coating layer by vapor deposition of ceramics is disclosed.

  Further, in Patent Publication 4, an ion source electrode for accelerating an ion beam is an ion source electrode mainly composed of a tantalum plate having a polymerized plate structure integrated by diffusion bonding of tantalum plates. In joining, the method of carrying out the diffusion joining to the joint surface via titanium is disclosed.

  Patent Document 5 discloses that a grooved plate and a flat plate, which are a pair of electrode elements facing each other in a vacuum vessel provided with a heater capable of diffusion bonding in a vacuum or gas atmosphere, are arranged. A method is described in which a liquid phase is formed by a eutectic reaction at a temperature lower than the melting point of the electrode element material to form a thin film layer that is solid-solved with the electrode element and integrated by diffusion bonding using the eutectic reaction. Yes. Here, the grooved plate is formed with a narrow groove constituting a cooling hole for flowing a coolant and a beam extraction hole for extracting an ion beam.

  The feature of this method is that by using the liquid phase generated by the eutectic reaction, diffusion bonding can be performed only by applying a relatively small pressure, so that the liquid phase diffuses and solidifies, and gaps and voids disappear. It is possible to obtain a good joint surface having excellent adhesion over the entire joint surface of both electrode elements without deforming the entire electrode, deforming or filling the cooling hole of the grooved plate. In addition, there is an advantage that the narrow groove formed for the cooling hole is deformed by the applied pressure to reduce the cooling efficiency, and the dimensional accuracy as a product is less likely to be lowered.

Japanese Patent Laid-Open No. 3-129638 JP 2008-078042 A JP-A-5-29093 JP-A-6-314600 Japanese Patent No. 2523742

  However, the ion source electrode described in Patent Document 1 is devised in order to prevent the molybdenum electrode plate from being corroded by cooling water and to extend the life of the product by coating nickel on the molybdenum electrode plate. However, a sound coating of nickel in the water channel of the molybdenum electrode plate is difficult and sometimes corrodes from the unhealthy part of the coating, which may cause a leakage of cooling water.

  The reason why the soundness of the coating is difficult to obtain is that the groove to be a water channel is very thin, 2 mm to 3 mm, and coating inside such a thin groove is required. Even if a state-of-the-art coating technique such as electroplating, PVD (physical vapor deposition), or CVD (chemical vapor deposition) is used as the coating method or means, it is difficult to coat the inside of the narrow groove. In addition, the groove shape is a square groove in order to increase the cooling efficiency, and it is very difficult to coat so that the coating thickness in the groove and in the corner portion is uniform and sound (defect-free).

  Each of the ion source electrodes in Patent Document 1, Patent Document 3, and Patent Document 4 is made of a refractory metal material such as molybdenum or tantalum, and its structure diffuses a grooved plate and a flat plate. They are integrated by joining. In order to diffusely bond a grooved plate made of molybdenum or tantalum having a high melting point and a flat plate, it is required to strictly observe conditions such as temperature, atmosphere, and pressure during the bonding. Furthermore, these conditions must be kept stable for a certain time.

  The temperature required for diffusion bonding is generally said to be 0.7 times or more of the melting point of the material or higher than the recrystallization temperature of the material. The atmosphere should be an atmosphere in which surface oxidation or the like of the material to be joined is not a problem at a temperature necessary for diffusion bonding. Therefore, bonding in a high vacuum or an inert gas atmosphere such as argon or helium is required. The appropriate pressure is determined by the surface roughness of the bonding surface and the bonding temperature. If the temperature is high, the applied pressure is small. If the temperature is low, the applied pressure must be set large. In addition, regarding the surface roughness, when the unevenness of the joint surface is fine, the applied pressure must be small, and conversely, when the unevenness of the joint surface is rough, the applied pressure must be set high.

  In short, contact (adhesion) between the joint surfaces is important. The time for maintaining this condition depends on the temperature, atmosphere, and pressure. That is, if the temperature is high and the pressure is high, the interdiffusion proceeds positively and the holding time is short. However, in the ion source electrode plate bonding by diffusion bonding, when the accuracy of the bonding surface that facilitates bonding, for example, when the surface roughness is kept at 5 S or less, buffing is required after machining, In order to maintain the flatness and also the cleanliness, care must be taken during storage during and after processing. In particular, the plate thickness of the ion source electrode plate is as thin as about 3 to 10 mm, for example, and it is difficult to pressurize the entire joint surface of this member uniformly and to control the pressure while suppressing deformation of the groove. Even if the device is made, it becomes a very complicated and expensive facility. In such diffusion bonding, the manufacturing cost is high and its reliability is low, and it is considered that uniform bonding over the entire bonding surface is difficult when the area is large such as an ion source electrode plate.

  Further, the one disclosed in Patent Document 5 is integrated by diffusion bonding using a eutectic reaction, and the feature is that a liquid phase generated by the eutectic reaction is used, and a relatively small pressure is applied. Diffusion bonding can be performed in this state. However, in order to integrate the members by diffusion bonding, it is necessary to heat all the members to a temperature range where diffusion bonding or eutectic reaction occurs. In this method, when a flat surface cannot be obtained on the bonding surface and the bonding surface is not sufficiently adhered in the heated state, a eutectic reaction does not occur, a liquid phase is not generated, and defective voids are generated there. there's a possibility that.

  On the other hand, this method may face the same problem as described in the joining of the electrode plates disclosed in the above-mentioned publications. That is, in the ion source electrode by diffusion bonding, when the accuracy of the bonding surface for facilitating bonding, for example, the surface roughness is kept at 5S or less, buffing is necessary after machining, and further, after undergoing these steps. But care must be taken to keep it flat and clean.

  In the structure described in Patent Document 2, a barrier layer having a groove is brazed, but in the brazing of the barrier layer and a heat-resistant material such as molybdenum, thermal deformation is likely to occur during brazing due to the difference in linear expansion coefficient. It is difficult to obtain the flatness required for an ion source electrode plate. In addition, when the product is used, the heat resistant material is difficult to be cooled because the contact area between the barrier layer near the beam hole and the heat resistant material is small when the beam hole is heated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a long-life ion source electrode having high cooling efficiency and excellent corrosion resistance.

  (1) The ion source electrode according to the present invention is a first and second heat-resistant electrode made of a heat-resistant metal material having a plurality of beam holes for extracting an ion beam and having at least one continuous groove. A plate is sandwiched between the first and second heat-resistant electrode plates and is tightly bonded to each of the first and second heat-resistant electrode plates so as to cover the peripheral wall of the groove, and is made of a corrosion-resistant metal material. And a barrier material that is disposed in the vicinity of the beam hole and is defined by a barrier material that covers the peripheral wall of the groove, and a coolant for cooling the first and second heat-resistant electrode plates flows therethrough, at least And a refrigerant channel arranged so that a part thereof enters the groove.

  In the present invention, since at least a part of the refrigerant flow path is disposed so as to enter the groove of the heat-resistant electrode plate (FIGS. 3, 4, 17 to 20), the refrigerant flow path, the beam hole, Thus, the heat-resistant electrode plate heated by the ion beam passing through the beam hole can be cooled more efficiently than before. Further, since the barrier material on the circumferential wall of the groove forming the coolant channel is made of a metal material having excellent corrosion resistance, the risk of the coolant channel being damaged by high temperature corrosion is reduced. Thus, the ion source electrode of the present invention has high cooling efficiency, and the risk of leakage of the refrigerant is reduced.

  (2) In the invention of (1), the barrier material is preferably solid phase diffusion bonded to the heat-resistant electrode plate using a hot isostatic pressing method. When the barrier material is diffusion bonded to the heat-resistant electrode plate using the hot isostatic pressing method, the soundness of the bonding surface is excellent, and the peripheral wall of the coolant channel formed inside the groove has a surface property with excellent corrosion resistance. Become. For this reason, the refrigerant flow path can withstand a high temperature corrosive environment, and refrigerant leakage (leakage) hardly occurs.

  (3) In the invention of (1), the barrier material is preferably joined to the heat-resistant electrode plate using a hot rolling method. When joining a barrier material to a heat-resistant electrode plate using a hot rolling method, as in (2) above, the joining surface is excellent in soundness and the peripheral wall of the coolant channel formed inside the groove is corrosion resistant. Excellent surface properties, the refrigerant flow path can withstand high temperature corrosive environments, and refrigerant leakage (leakage) hardly occurs.

  (4) In the invention according to any one of (1) to (3), the barrier material is preferably made of copper or a copper alloy. For example, it is desirable to use pure copper having a purity of 99.99% or more. As the copper alloy, for example, a Cu-Cr alloy, a Cu-Ag alloy, a Cu-Cr-Zr alloy, a Cu-Ni alloy, or the like can be used. This is because these copper and copper alloys are excellent in high-temperature corrosion resistance and have high reliability even in an environment with a high heat load.

  (5) In any one of the inventions (1) to (3), the barrier material is preferably made of aluminum or an aluminum alloy. For example, it is desirable to use pure aluminum having a purity of 99.99% or more. As the aluminum alloy, for example, an Al—Cu alloy, an Al—Cu—Mg alloy, an Al—Cu—Si alloy, an Al—Si—Mg alloy, or the like can be used. This is because these aluminum and aluminum alloys have excellent high-temperature corrosion resistance and high reliability even in an environment with a high heat load.

  (6) In the invention according to any one of (1) to (5), it is preferably made of any one of molybdenum, titanium, and tantalum. This is because the use of a material having a small linear expansion coefficient such as molybdenum, titanium, or tantalum greatly reduces thermal deformation even in a heating test of the ion source electrode under a high heat load.

  (7) In any one of the inventions (1) to (6), one of the first and second heat-resistant electrode plates is a grooved flat plate having a groove on the joint surface with the barrier material, and the other is a barrier. It can be a flat plate without a groove on the joint surface with the material (FIGS. 3 and 4).

  (8) In any one of the inventions (1) to (6), both of the first and second heat-resistant electrode plates can be formed as a grooved flat plate having a groove on the joint surface with the barrier material ( 17 and 18).

  (9) In the invention according to any one of (1) to (8), each of the joining surfaces of the first and second heat-resistant electrode plates and the barrier material may further have a heat dissipation uneven structure (see FIG. 19, FIG. 20). If the joint surface between the heat-resistant electrode plate and the barrier material has a heat dissipation uneven structure, the cooling efficiency of the electrode is further improved and the life is extended.

  (10) An ion source according to the present invention includes the ion source electrode according to any one of (1) to (9) and a filament that generates a discharge for generating ions from the first gas. A plasma generation unit, and a neutralization cell that neutralizes the ions by causing a second gas to act on the ions generated by the plasma generation unit (FIGS. 1, 3, 4, and 17). To FIG. 20).

  According to the present invention, the cooling efficiency is greatly improved. For this reason, the reliability of the high heat load heat removal device is increased, and the life of the electrode is extended.

  Moreover, according to this invention, the danger that a refrigerant | coolant leaks from a flow path will reduce. ADVANTAGE OF THE INVENTION According to this invention, corrosion of the heat-resistant electrode plate by the cooling water which was the fault of the conventional electrode for ion sources can be prevented, and the leakage of cooling water can be avoided.

The internal perspective sectional drawing which shows the outline | summary of the whole neutral particle injection apparatus which has the ion source of this invention. An external view of the ion source electrode. Sectional drawing which shows the electrode for ion sources which concerns on the 1st Embodiment of this invention. FIG. 4 is a partial enlarged cross-sectional view showing a main part of the ion source electrode in FIG. 3. Process sectional drawing for demonstrating the manufacturing method of the electrode for ion sources of this invention. Process sectional drawing for demonstrating the manufacturing method of the electrode for ion sources of this invention. Process sectional drawing for demonstrating the manufacturing method of the electrode for ion sources of this invention. Process sectional drawing for demonstrating the manufacturing method of the electrode for ion sources of this invention. Sectional drawing which shows the manufacturing method of the electrode for ion sources which is embodiment of this invention. The block sectional view showing the device used for manufacture of the electrode for ion sources of the present invention. Process sectional drawing for demonstrating the manufacturing method of the electrode for ion sources of this invention. Process sectional drawing for demonstrating the manufacturing method of the electrode for ion sources of this invention. Process sectional drawing for demonstrating the manufacturing method of the electrode for ion sources of this invention. Process sectional drawing for demonstrating the manufacturing method of the electrode for ion sources of this invention. Process sectional drawing for demonstrating the manufacturing method of the electrode for ion sources of this invention. Process sectional drawing for demonstrating the manufacturing method of the electrode for ion sources of this invention. Sectional drawing which shows the electrode for ion sources which concerns on the 2nd Embodiment of this invention. The fragmentary expanded sectional view which shows the principal part of the electrode for ion sources of FIG. Sectional drawing which shows the electrode for ion sources which concerns on the 3rd Embodiment of this invention. The partial expanded sectional view which shows the principal part of the electrode for ion sources of FIG. (A)-(c) is a cross-sectional view which shows the refrigerant | coolant flow path of a modification, respectively. The principal part expanded sectional view which shows the conventional electrode for ion sources.

  Hereinafter, various preferred embodiments for carrying out the present invention will be described with reference to the accompanying drawings. First, the outline of the configuration of the relevant part of the fusion apparatus in which the ion source electrode of the present invention is used will be described.

  As shown in FIG. 1, an ion source 32 of a neutral particle injection device 31 used in a nuclear fusion device has a filament 34 in a plasma generator 35 having a filament 34 into which a first gas 33 such as hydrogen is introduced. Plasma is generated by performing an arc discharge through. Then, ions ionized by the first gas 33 in the plasma are extracted from the plasma by an electric field formed by applying a high voltage to each electrode 25 of the electrode array 36, and accelerated. An ion beam 40 is generated.

  Since the ion beam 40 is bent by the magnetic field of the coil of the fusion apparatus as it is, it passes through the neutralization cell 39 filled with the second gas, and the kinetic energy is generated by the collision reaction between the ions and the second gas. While being stored, it is converted into a neutral particle beam 41 and incident on the core plasma 42.

  The electrode array 36 for accelerating ions in the ion source described above is composed of three or five (not shown) electrodes 25 arranged in parallel to each other, and a plurality of ion beam extraction holes 23 formed in the electrode 25. An ion beam is extracted from the plasma through the electrode. In particular, the first-stage electrode 25 closest to the ion source is in direct contact with the high-temperature ion beam 40. For this reason, the electrode 25 is provided with a cooling channel that lowers the thermal load of the electrode itself and improves the durability. Usually, the cooling channel is provided between a plurality of ion beam extraction holes formed in order to effectively perform cooling. As shown in FIG. 2, in the main surface of the ion source electrode 25, a large number of beam holes 23 for extracting an ion beam from plasma are regularly arranged.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 3, the ion source electrode 25 of the present embodiment has a Mo heat resistant electrode plate 1, a Cu barrier material 4, a stepped Cu barrier material 5, and a grooved Mo heat resistant electrode plate 3 stacked in this order and joined together. It is made. A plurality of beam holes 23 are formed through the electrode 25 formed of such a laminate. A step of a Cu barrier material 5 is fitted into the groove 2 of the Mo heat-resistant electrode plate 3. A coolant channel 22 is formed in the region of the fitting portion between the groove 2 and the step. The refrigerant flow path 22 has a rectangular cross section, three of the four peripheral walls are defined by the grooved Cu flat plate 5, and the remaining one peripheral wall is defined by the Cu flat plate 4. A part of the refrigerant flow path 22 enters the groove 2 of the Mo heat resistant electrode plate 3 with the groove. The cooling efficiency of the Mo heat-resistant electrode plate 3 increases as the refrigerant channel 22 enters more.

  Next, a method for manufacturing the ion source electrode 25 of the present embodiment will be described with reference to FIGS.

  FIG. 5 is a diagram showing a basic component shape before manufacturing that constitutes the ion source electrode according to the first embodiment of the present invention. 6-10 is a figure which shows the manufacturing process.

As shown in FIG. 5, the ion source electrode is manufactured by a flat plate 1 made of molybdenum having a melting point of 2630 ° C., a linear expansion coefficient of 5.43 × 10 ⁻⁶ · ° C. ⁻¹ at 25 ° C., and a width. Further, a grooved flat plate 3 in which a plurality of grooves 2 each having a depth of about 2 mm are formed in parallel with each other at a predetermined interval is manufactured by using machining or the like.

  Next, as shown in FIG. 6, one surface of the flat plate 1 is covered with the barrier material 4, and the groove inside 2 and one surface of the grooved flat plate 3 are covered with the barrier material 5. In the present embodiment, the barrier materials 4 and 5 used were rolled plates of pure copper (Cu) having excellent corrosion resistance different from those of the heat resistant electrode plates 1 and 3.

  FIG. 7 shows a case where the joining process is performed in a high-temperature and high-pressure atmosphere in order to join the flat plate 1 and the grooved flat plate 3 prepared in FIG. 6 and the respective corrosion-resistant barrier materials 4 and 5. A state in which a ceramic sheet 6 as a release material is inserted and disposed in the middle so that the copper of the corrosion-resistant barrier materials 4 and 5 are not joined to each other when the same treatment is performed for cost reduction is shown.

  In order to join the flat plate 1 and the corrosion-resistant barrier material 4 and the grooved flat plate 3 and the corrosion-resistant barrier material 5 using the hot isostatic pressing method at high temperature and high pressure, the respective joining surfaces are used. In order to prevent high-temperature and high-pressure gas from entering, seal welding is performed in a container. A joining container 7 shown in FIG. 8 includes an upper plate 8, side plates 9 and 10, and a bottom plate 11. A stainless steel plate having excellent weldability and availability was used as the material for the bonding container 7.

  FIG. 9 shows the joining container 7 and the seal welds 12a, 12b, 12c, and 12d using an electron beam welder (not shown) that is performed in a vacuum. In the electron beam welding, in order to completely deaerate the air in the bonding container 7, vacuum evacuation was performed for 30 minutes or more, and then seal welding was performed. The soundness of the seal welds 12a to 12d was confirmed using a weld bead appearance inspection, a fluorescent flaw detection test, or a helium leak test as necessary.

Said electrode assembly 25a is accommodated in the joining container 7, and this is inserted in the hot isostatic pressing apparatus 13 shown in FIG. Subsequently, the vacuum pump 14 was started and the inside of the apparatus 13 was deaerated by pump exhaust driving. After the degree of vacuum reaches about 10 ⁻² Pa, the vacuum pump 14 is stopped, the apparatus 13 is filled with argon gas as an inert gas, and the high pressure pump 15 is used to set the initial pressure to about 10 MPa. After that, the temperature was increased using the heater 16 in the apparatus.

  As the internal temperature of the device 13 increased, the gas pressure inside the device increased, and the high-pressure pump 15 was repeatedly driven and stopped. The joining conditions were such that the temperature was 900 ° C., the gas pressure was 147 MPa, and the holding time was 2 hours. In addition, although the arrow 17 in a figure shows the direction where gas pressure acts, the joining container 7 can be pressurized whole with isotropic pressure. Thereafter, the heater 16 was turned off, and the operation of cooling and lowering the pressure to normal temperature and normal pressure was performed while recovering the gas released along with the discharge of the high pressure gas in the hot isostatic pressurizer 13.

  After the pressure and temperature in the hot isostatic pressurizer 13 become close to atmospheric pressure and room temperature, respectively, the lid (not shown) of the hot isostatic pressurizer 13 is opened, and the bonding container 7 is taken out.

  The taken-out joining container 7 removes the seal welds 12a, 12b, 12c, and 12d by mechanical cutting or the like, and takes out the electrode assembly 25a from the inside of the joining container 7. The taken-out electrode assembly 25a was easily separated from the bonding container 7 through the ceramic sheet 6 and the like so as not to be directly bonded to the bonding container 7 even under high temperature and high pressure conditions.

  As described above, the first composite plate 18 in which the barrier material 4 is bonded to the flat plate 1 is formed, and at the same time, the second composite plate 19 in which the barrier material 5 is bonded to the grooved flat plate 3 is formed. It should be noted that the joint between the Mo flat plate 1 and the Cu barrier material 4 and the joint between the grooved Mo flat plate 3 and the Cu barrier material 5 are metallurgically strong by hot isostatic pressing, respectively. It is in the state joined to.

  Further, the first composite plate 18 and the second composite plate 19 need to be joined to form a refrigerant flow path that allows further direct cooling. Therefore, first, as shown in FIGS. 11 and 12, each layer of the corrosion-resistant barrier material 4 is cut or ground so as to have a thickness of about 0.3 to 0.5 mm to obtain a predetermined thickness. Machining was performed while paying close attention to flat finishing so that certain corrosion-resistant barrier layers could be joined together. A flat plate 18A and a grooved flat plate 19A shown in FIGS. 11 and 12 are formed by processing the corrosion-resistant barrier layers 4A and 5A to 0.3 to 0.5 mm, respectively. In particular, in order to machine the inside of the grooved flat plate 19A to a thickness of 0.3 to 0.5 mm, it was used when machining the grooved flat plate 3 and the groove 2 shown in FIG. Although not shown with the NC program, machining was performed to a predetermined thickness using a machining reference point.

  The reason why the thickness of the barrier materials 4A and 5A is about 0.3 to 0.5 mm is that it is suitable for joining the flat plate 18A and the grooved flat plate 19A in consideration of the machining accuracy of the groove processing and the reliability of corrosion resistance or corrosion resistance. It is the thickness of the layer judged to be the thickness.

As shown in FIG. 13, the flat plate 18A and the grooved flat plate 19A machined with the corrosion-resistant barrier layer are then integrated by melting and brazing a brazing material necessary for joining. Although not shown in the figure, brazing is performed using a vacuum furnace, and the degree of vacuum is 10 ^-2 Pascal or less, and the brazing material used is 0.1 mm thick of silver brazing (silver 71-73%, remaining copper). The foil 20 was used. The brazing was performed under a heating and holding condition of 830 ° C. for 15 minutes.

  The refrigerant flow path 22 is formed in the groove 19 g of the grooved flat plate 4 by vacuum brazing the flat plate 1 and the grooved flat plate 4. As a result, an electrode assembly 21 having the refrigerant flow path 22 shown in FIG. 14 is obtained. Thereafter, beam holes 23 necessary for the ion source electrode were drilled by machining. FIG. 15 shows a cross-sectional view of the ion source electrode in which the beam hole is processed. In the electrode assembly 21, copper headers 24a and 24b for passing the coolant through the cooling holes 22 are joined by brazing portions 28, whereby the final shape ion source electrode 25 shown in FIG. 16 is obtained. It is done. In such an ion source electrode 25, molybdenum materials 1 and 3 are arranged on both surfaces, and a refrigerant flow path 22 is provided in the inside thereof, and a peripheral wall (surface in contact with cooling water) of the refrigerant flow path 22 is provided on the inside. The structure is provided with a corrosion-resistant barrier material 20b. The header 24a on one side is formed with an inlet 24c communicating with a cooling water supply source as a refrigerant supply means, and the outlet on which used cooling water that has passed through the refrigerant flow path 22 is discharged on the header 24b on the other side. 24d is formed.

(Example)
An embodiment of the present invention will be described with reference to FIGS.

  The ion source electrode 25 of the embodiment includes a Mo flat plate (heat resistant electrode plate) 1, a Cu flat plate (barrier material) 4, a grooved Cu flat plate (barrier material) 5, and a grooved Mo flat plate (heat resistant electrode plate) 3. They are stacked in this order and joined to each other, and have a plurality of beam holes 23 penetrating the laminated body and a refrigerant flow path 22 through which the refrigerant flows. The refrigerant flow path 22 is defined by the grooved flat plate 5 and the flat flat plate 4 which are barrier materials, and communicates with the supply line of the refrigerant supply means via the headers 24a and 24b.

  The size of each part of the example electrode 25 is listed below.

1) Total electrode thickness t1: 3 mm
2) Thickness t2: 0.3 mm
3) Groove depth (step) t3: 1.2 mm
4) Thickness t4: 1.5mm
5) Thickness t5: 0.3 mm
6) Thickness t6: 1.7 mm
7) Thickness t7: 0.7mm
8) Refrigerant flow path depth d2: 0.5 mm
9) Width of refrigerant flow path W1: 2 mm
10) Diameter of beam hole: 7mm
The operation and effect of the first embodiment will be described below.

  Although metal spraying or plating, which is a conventional method even with the same copper material, is porous although it is dense and not a complete solid metal structure, it is inferior in corrosion resistance, but the present invention, as shown in FIG. Three surfaces, which are the inner surfaces of the refrigerant flow path, are formed by using a hot isostatic pressing method to form a barrier layer made of a rolled metal having excellent corrosion resistance on the flat plate and grooved flat plate constituting the ion source electrode. In addition, since a pressing force can be applied, the barrier layer to be adhered to the inner surface of the refrigerant flow path can be completely adhered, that is, strong and excellent in corrosion resistance, without requiring high surface accuracy. In particular, the barrier layer inside the groove of the grooved flat plate can be bonded stronger and sounder than the conventional method by taking advantage of the isotropic pressurization that is omnidirectional pressurization because of the hot isostatic pressurization method. it can. Therefore, as shown in the cross-sectional view of FIG. 4, the coolant channel 22 and the coolant around the coolant channel, which was a defect of the molybdenum electrode plate in which the cooling efficiency is improved by passing pure water through the coolant channel 22. Corrosion due to corrosion is prevented by providing a barrier layer made of copper, which is a corrosion-resistant metal, on the inner week surface of the refrigerant flow path in contact with cooling water using pure water, and water leaks from the cooling holes by preventing corrosion. As a result, an ion source electrode having a healthy barrier layer for the purpose of corrosion resistance can be provided.

  Furthermore, since the ion source electrode is used in a vacuum environment, the present invention is effective not only for water leakage in the refrigerant flow path but also for countermeasures against ion source troubles such as vacuum leakage. In other words, it is possible to avoid troubles such as water leaks or vacuum leaks. The use of heat-resistant metal and molybdenum with a low coefficient of linear expansion also ensures stable and stable beam holes in test operations with high heat loads caused by ion source beam irradiation. Since the irradiation experiment of the irradiated beam can be performed for a long time or repeatedly, the efficiency of the irradiation experiment can be improved. There is no concern of cooling water leakage due to corrosion by the reject medium. Accordingly, it is possible to provide an ion source electrode plate with improved heat resistance and longer life while improving the reliability of the molybdenum ion source electrode plate assumed to be operated at a high heat load.

  In this example, a copper metal generally known as a corrosion-resistant metal was selected as the corrosion-resistant barrier layer. However, it is not limited to copper, but a metal excellent in bondability with molybdenum, for example, silver, which is a little expensive. Even with a relatively low melting point metal such as a plate of aluminum or nickel, or aluminum and an aluminum alloy, the same action and effect as copper and a copper alloy can be obtained. Therefore, by combining and optimizing the barrier layer according to the test environment of heat load or the number of repetitions as the ion source electrode, an inexpensive and highly reliable ion source electrode can be provided.

  As described above, according to the ion source electrode in the present embodiment, the forced cooling type molybdenum ion source electrode does not directly contact molybdenum with pure water of the cooling medium. There is no corrosion, and a longer life can be achieved compared to conventional diffusion bonding type molybdenum electrodes. In addition, since the barrier layer formed on the molybdenum flat plate and the grooved flat plate is metallically bonded by a hot isostatic pressing method, a strong barrier layer can be obtained, so that a reliable ion source electrode can be provided. it can.

Table 1 shows the physical properties of various metal materials used for the heat-resistant electrode plate and barrier material of the present invention. Molybdenum (Mo), titanium (Ti) or tantalum (Ta) is suitable for the heat-resistant electrode plate. This is because these materials have a high melting point and a small linear expansion coefficient. Copper (Cu), nickel (Ni) or aluminum (Al) is suitable for the barrier material. This is because these materials have high thermal conductivity and excellent corrosion resistance to water.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, description of the part which this embodiment is common in the said embodiment is abbreviate | omitted.

  The ion source electrode 25A of this embodiment includes a grooved Mo flat plate (heat resistant electrode plate) 1A, a stepped Cu flat plate (barrier material) 4A, a stepped Cu flat plate (barrier material) 5A, and a grooved Mo flat plate (heat resistant electrode plate). 3A are stacked in this order and joined to each other, and have a plurality of beam holes 23 penetrating the laminated body and a refrigerant flow path 22A through which the refrigerant flows. The refrigerant flow path 22A is defined by the stepped flat plates 4A and 5A, which are barrier materials, and communicates with the supply line of the refrigerant supply means via the headers 24a and 24b.

(Example)
The size of each part of the example electrode 25A is listed below.

1) Total electrode thickness t1: 3 mm
2) Thickness t2, t8: 0.3mm
3) Groove depth (step) t3, t9: 1.2mm
4) Thickness t4: 1.5mm
5) Thickness t5: 0.3 mm
6) Thickness t6: 1.7 mm
7) Thickness t7: 0.7mm
8) Refrigerant flow path depth d2: 0.5 mm
9) Width of refrigerant flow path W1: 2 mm
10) Diameter of beam hole: 7mm
(Third embodiment)
A third embodiment of the present invention will be described with reference to FIGS. 19 and 20. In addition, description of the part which this embodiment is common in the said embodiment is abbreviate | omitted.

  The ion source electrode 25B of this embodiment includes a grooved Mo flat plate (heat resistant electrode plate) 1B, a stepped Cu flat plate (barrier material) 4B, a stepped Cu flat plate (barrier material) 5B, and a grooved Mo flat plate (heat resistant electrode plate). 3B are stacked in this order and joined to each other, and have a plurality of beam holes 23 penetrating the laminated body and a refrigerant flow path 22B through which the refrigerant flows. The refrigerant flow path 22B is defined by stepped flat plates 4B and 5B, which are barrier materials, and communicates with the supply line of the refrigerant supply means via the headers 24a and 24b.

  Furthermore, in this embodiment, the joining surface of grooved Mo flat plate (heat resistant electrode plate) 1B and stepped Cu flat plate (barrier material) 4B, and stepped Cu flat plate (barrier material) 5B and grooved Mo flat plate (heat resistant electrode) Plate) A heat dissipation concavo-convex structure P is respectively formed on the joint surface with 3B to further improve the cooling efficiency of the electrodes.

  By adopting such a shape, it can be expected that the cooling efficiency of the electrode is increased and the structure is strong against the destruction of the joint due to repeated stress caused by the difference in linear expansion coefficient.

  The size of each part of Example electrode 25B is listed below.

1) Total electrode thickness t1: 3 mm
2) Thickness t2, t8: 0.3mm
3) Groove depth (step) t3, t9: 1.2mm
4) Thickness t4: 1.5mm
5) Thickness t5: 0.3 mm
6) Thickness t6: 1.7 mm
7) Thickness t7: 0.7mm
8) Refrigerant flow path depth d2: 0.5 mm
9) Width of refrigerant flow path W1: 2 mm
10) Diameter of beam hole: 7mm
11) Length of heat dissipation uneven structure P: 0.1 mm
(Modification)
In the above embodiment, the example in which the cross-sectional shape of the refrigerant channel is rectangular has been described. However, the present invention is not limited to this, and a flat plate having a U-shaped groove as shown in FIG. A flat plate 4 may be joined to 5c to form a refrigerant passage 22c having a semicircular or semi-elliptical cross section, and the flat plate 4 may be formed on a flat plate 5d having a V-shaped groove as shown in FIG. May be used to form a refrigerant channel 22d having a triangular cross-sectional shape, or a flat plate 4 may be bonded to a flat plate 5e having a trapezoidal groove as shown in FIG. The channel 22e may be used.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described.

  The fourth embodiment uses a hot rolling method in which a joining method for forming a barrier layer on the joining surface of a flat plate and a flat plate with a groove and the surface in contact with the cooling water inside the groove is not shown in the figure, Since steel can be charged as a raw material, a highly productive manufacturing method can be provided as an ion source electrode material, and an inexpensive material can be provided.

  The action and effect of this method is that the hot rolling method is used, and the vacuum evacuation in the bonding vessel and the high-density sealing technology required for the hot isostatic pressing method are used for electron beam welding machines, etc. Expensive equipment is not required, and hermetic welding such as tungsten inert gas welding is possible. The joining mechanism of this hot rolling method is more aggressive than the static joining mechanism of the hot isostatic pressing method by a dynamic joining mechanism such as oxide discharge due to deformation of the joining interface during rolling. Since interdiffusion is promoted, the management standard of the joint surface before joining can be relaxed, so that the manufacturing process can be afforded.

1 ... Heat-resistant electrode plate (flat plate), 1A, 1B ... Heat-resistant electrode plate (grooved plate),
2, 2A, 2B ... groove,
3, 3A, 3B ... heat-resistant electrode plate (flat plate with groove),
4, 5, 5c, 5d, 5e ... barrier material (corrosion resistant barrier layer),
6, 6a ... ceramic sheet (release material),
7 ... Joining container, 8 ... Top plate, 9, 10 ... Side plate, 11 ... Bottom plate,
12a, 12b, 12c, 12d ... welds, 13 ... hot isostatic pressing device,
14 ... Vacuum pump, 15 ... High pressure pump, 16 ... Heater, 17 ... Pressure direction,
18 ... Composite plate, 18a ... Heat-resistant electrode plate (flat plate), 18b ... Barrier material,
19 ... Composite plate, 19a ... Heat-resistant electrode plate (flat plate with groove), 19b ... Barrier material,
20 ... wax foil (barrier material),
21 (25a) ... electrode assembly,
22, 22A, 22B, 22c, 22d, 22e ... refrigerant flow path,
23 ... Beam hole, 24a, 24b ... Header, 24c ... Refrigerant inlet, 24d ... Refrigerant outlet,
25 ... Ion source electrode,
28 ... brazing part,
31 ... Neutral particle injection device, 32 ... Ion source, 33 ... Gas, 34 ... Filament,
35 ... Plasma generator, 36 ... Accelerator (electrode array), 37 ... High voltage power supply,
39 ... Neutralization cell, 40 ... Ion beam, 41 ... Neutral particle beam, 42 ... Core plasma, P ... Heat radiation uneven structure.

Claims (10)

A plurality of beam holes for extracting an ion beam, and at least one of the first and second heat-resistant electrode plates made of a heat-resistant metal material having a continuous groove;
A barrier material that is sandwiched between the first and second heat-resistant electrode plates and is tightly bonded to each of the first and second heat-resistant electrode plates so as to cover the peripheral wall of the groove and is made of a corrosion-resistant metal material When,
The periphery is defined by a barrier material that is disposed in the vicinity of the beam hole and covers the peripheral wall of the groove, and a coolant for cooling the first and second heat-resistant electrode plates flows therethrough, and at least a part of the groove is formed. A refrigerant flow path arranged so as to enter into the inside,
An ion source electrode comprising:   2. The ion source electrode according to claim 1, wherein the barrier material is solid-phase diffusion bonded to the heat-resistant electrode plate using a hot isostatic pressing method.   The electrode for an ion source according to claim 1, wherein the barrier material is bonded to the heat-resistant electrode plate using a hot rolling method.   The ion source electrode according to claim 1, wherein the barrier material is made of copper or a copper alloy.   4. The ion source electrode according to claim 1, wherein the barrier material is made of aluminum or an aluminum alloy. 5.   6. The ion source electrode according to claim 1, wherein the heat-resistant electrode plate is made of molybdenum, titanium, or tantalum.   One of the first and second heat-resistant electrode plates is a grooved flat plate having the groove on the bonding surface with the barrier material, and the other is a flat plate without the groove on the bonding surface with the barrier material. The ion source electrode according to claim 1, wherein the ion source electrode is provided.   The ion source according to any one of claims 1 to 6, wherein both the first and second heat-resistant electrode plates are grooved flat plates having the groove on the joint surface with the barrier material. Electrode.   9. The ion source electrode according to claim 1, further comprising a heat dissipation uneven structure on each joint surface between the first and second heat-resistant electrode plates and the barrier material. An ion source electrode according to any one of claims 1 to 9,
A plasma generating unit having a filament for generating a discharge for generating ions from the first gas;
A neutralization cell that neutralizes the ions by causing a second gas to act on the ions generated by the plasma generation unit;
An ion source comprising:

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