Electromagnetic field control components

Abstract

A component for electromagnetic field control comprises: an insulating component, which is composed of a cylindrical ceramic and has a plurality of through holes extending along the axial direction; a conductive component, which is composed of metal and blocks the through holes so as to have an opening portion opening at the outer periphery of the insulating component; a power supply terminal connected to the conductive component, and the inner wall surface of the through hole comprises: an inclined surface, the width between the inner walls facing each other gradually increases from the inner periphery of the cylindrical insulating component toward the outer periphery; and a vertical surface, which is located on the inner periphery side of the insulating component and the width between the inner walls facing each other is constant.

Description

Technical Field

[0001] The present disclosure relates to an electromagnetic field control member used in an accelerator or the like for accelerating charged particles such as electrons and heavy particles. Background Art

[0002] In the past, electromagnetic field control components used in accelerators for accelerating charged particles such as electrons and heavy particles required high speed, high magnetic field output, and high repeatability. In order to improve these performances, Shiori Mitsuda et al. of the High Energy Accelerator Research Institute proposed a ceramic chamber with integrated pulsed-magnet (hereinafter referred to as CCiPM) (Non-Patent Document 1).

[0003] The CciPM has a cylindrical insulating member made of ceramic, and a substrate-shaped conducting member is buried in a through hole formed along the axial direction of the insulating member and penetrating the thickness direction of the insulating member. Moreover, the conducting member acts as a part of a partition wall separating the inside and outside of the insulating member, ensuring the airtightness of the inside of the insulating member.

[0004] In order to maintain the airtightness of the space inside the insulating member for a long time, the applicant has previously proposed an electromagnetic field control member, which comprises: an insulating member, which is made of cylindrical ceramic and has a plurality of through holes along the axial direction; a conductive member, which is made of metal and blocks the through holes so as to have an opening portion opening at the outer periphery of the insulating member; and a power supply terminal, which is connected to the conductive member, and is separated from the inner wall of the insulating member forming the through hole, and has a first end and a second end in the axial direction, and at least one of the first end and the second end is farther away from the inner wall than the central part of the power supply terminal (Patent Document 1). Patent Document 1 records that the width between the inner walls gradually increases from the inner periphery of the insulating member toward the outer periphery.

[0005] Prior Art Literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2018 / 174298

[0008] Non-patent literature

[0009] Non-patent document 1: Mitsuda Shiori et al., "Performance test of ceramic chamber integrated pulse magnet beam in KEK-PF ring beam conveyor dump line" Summary of the invention

[0010] The electromagnetic field control component disclosed in the present invention comprises: an insulating component, which is composed of a cylindrical ceramic and has a plurality of through holes extending along the axial direction; a conductive component, which is composed of metal and seals the through holes so as to have an opening portion opening at the outer periphery of the insulating component; and a power supply terminal connected to the conductive component, the inner wall surface of the through hole comprises: an inclined surface, the width between the inner walls facing each other gradually increases from the inner periphery of the cylindrical insulating component toward the outer periphery; and a vertical surface, which is located on the inner periphery side of the insulating component and the width between the inner walls facing each other is constant. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1A It is a front view showing an electromagnetic field control member according to one embodiment of the present disclosure.

[0012] Figure 1B yes Figure 1A AA′ line section view.

[0013] Figure 1C yes Figure 1A BB′ line section view.

[0014] Figure 2A yes Figure 1B CC′ line section view.

[0015] Figure 2B yes Figure 2A An enlarged view of the T section.

[0016] Figure 3 yes Figure 1B An enlarged view of the Q section in FIG.

[0017] Figure 4 It is an enlarged view of the S portion in FIG2 .

[0018] Figure 5 Yes means Figure 4 An exploded perspective view of the blades and blade connecting components.

[0019] Figure 6 It is a front view of the flange shown in FIG. 1 . DETAILED DESCRIPTION

[0020] Hereinafter, an electromagnetic field control member according to an embodiment of the present disclosure will be described with reference to the drawings. In this example, an example of CCiPM (ceramic cavity integrated pulse magnet) is described as an embodiment of the electromagnetic field control member.

[0021] Figure 1AThe electromagnetic field control member 100 according to one embodiment of the present disclosure as CCiPM is shown. The electromagnetic field control member 100 shown in FIG1 includes an insulating member 1 and flanges 2 and 2 attached to both ends of the insulating member 1, respectively.

[0022] The flanges 2, 2 are members connected to a vacuum pump (not shown) for evacuating the space 14 surrounded by the inner periphery of the insulating member 1. Figure 6 As shown in FIG. 1 , the flange 2 includes an annular base 2a and a plurality of extended protrusions 2b extending radially from the outer peripheral surface of the annular base 2a. The extended protrusions 2b are joined to the outer peripheral surface of the annular base 2a by TIG welding, which is one type of arc welding. Figure 6 In the example shown, four are provided at equal intervals along the circumferential direction. The extension protrusion 2b has an insertion hole 2c having an internal thread portion along the thickness direction, and the shaft 3 having an external thread portion is inserted into the insertion hole 2c, and nuts (not shown) are used to tighten from both sides of the thickness direction of the extension protrusion 2b, thereby connecting the flanges 2, 2 respectively mounted on both ends of the insulating member 1 to each other.

[0023] The annular base 2a has mounting holes 2d for connection with a flange (not shown) on the vacuum pump side at equal intervals in the circumferential direction. Fastening members such as bolts are inserted into the mounting holes 2d to fasten the flanges to each other.

[0024] The flange 2, the shaft 3 and the nut may include austenitic stainless steel. Austenitic stainless steel is non-magnetic, and therefore, the magnetic influence generated by the flange 2 can be reduced relative to the electromagnetic field control component 100. In particular, the flange 2 may include SUS304L or SUS304L. SUS304L and SUS304L are stainless steels that are not susceptible to intergranular corrosion. Therefore, even if the annular base 2a and the extended protrusion 2b are TIG-welded to the outer peripheral surface of the annular base 2a, intergranular corrosion is not likely to occur, and the airtightness of the annular base 2a is not likely to be damaged. The TIG welding of the extended protrusion 2b to the outer peripheral surface of the annular base 2a may be either intermittent welding or continuous welding along the thickness direction.

[0025] 1(a) is connected to the left end face of the insulating member 1 via a sleeve 21a. Similarly, the inner peripheral surface of the right flange 2 is connected to the right end face of the insulating member 1 via a sleeve 21b.

[0026] The sleeves 21 a and 21 b are made of Fermi alloy, Fe—Ni alloy, Fe—Ni—Cr—Ti—Al alloy, Fe—Cr—Al alloy or Fe—Co—Cr alloy, and are annular bodies having an L-shaped cross section including the central axis of the insulating member 1 .

[0027] The outer peripheral surfaces of the sleeves 21a and 21b facing the flange 2 are provided with a metal layer (not shown) mainly composed of nickel. Both end surfaces of the insulating member 1 are provided with a metallized layer (not shown) mainly composed of molybdenum and containing manganese.

[0028] The sleeves 21 a and 21 b respectively join the end surface of the insulating member 1 having the metallized layer to the inner peripheral surface of the flange 2 by means of brazing material, thereby combining the insulating member 1 and the flange 2 .

[0029] like Figure 1A The AA' line section view is Figure 1B And the BB′ line cross-sectional view is Figure 1C As shown, the insulating member 1 is made of cylindrical ceramics. The insulating member 1 has a plurality of through holes 4 extending in the axial direction. Here, the axial direction refers to a direction along the central axis of the insulating member 1 made of cylindrical ceramics.

[0030] The insulating member 1 is provided with a plurality of first power supply terminals 5 and second power supply terminals 6 at both ends. The first power supply terminal 5 is a terminal for power supply. Figure 1B As shown, they are connected to external devices via wires 8. In addition, two adjacent second power supply terminals 6 are electrically connected to each other via wires 7.

[0031] Respectively Figure 1B The CC' line cross-sectional view is Figure 2A and Figure 1B The Q part of the amplified Figure 3 As shown in FIG. 1 , a conductive member 9 is disposed in the through hole 4. The conductive member 9 includes a metal such as copper, for example, oxygen-free copper (for example, alloy number C1020 specified in JIS H 3100: 2012 or alloy number C1011 specified in JIS H 3510: 2012), and extends in the axial direction together with the through hole 4. Figure 3 As shown, the conductive member 9 blocks the through hole 4 to form an opening 10 opened at the outer periphery of the insulating member 1. By blocking the through hole 4 with the conductive member 9, the airtightness of the space 11 surrounded by the inner periphery of the insulating member 1 is ensured.

[0032] Here, the axial end surfaces of the conductive member 9 may be curved surfaces extending in the axial direction in a plan view. If the axial end surfaces of the conductive member 9 are in such a shape, the thermal stress remaining near the axial end surfaces of the conductive member 9 can be reduced even if heating and cooling are repeated.

[0033] The conducting member 9 ensures a conductive area for flowing an induced current, which is excited to accelerate or deflect electrons, heavy particles, etc. moving in the space 11. The inner peripheral side of the insulating member 1 of the conducting member 9 may also be a plane, but Figure 3As shown, it is preferably bent along the inner circumference of the insulating member 1 .

[0034] The first power supply terminal 5 and the second power supply terminal 6 are respectively connected to the conductive member 9 in the through hole 4 of the insulating member 1 in order to supply power from an external device to the conductive member 9 near both ends of the conductive member 9 arranged in the axial direction.

[0035] In addition, as shown in Figure 2, Figure 3 As shown, metallization layers 12 are formed on the inner walls of the insulating members 1 that face each other across the through hole 4. The metallization layers 12 are formed from one end surface where the through hole 4 is formed in the axial direction to the other end surface.

[0036] The metallization layer 12 may be, for example, a layer containing molybdenum as a main component and manganese. Alternatively, a metal layer containing nickel as a main component may be provided on the surface of the metallization layer 12. Alternatively, a plating layer may be formed instead of the metallization layer 12.

[0037] The thickness of the metallization layer 12 is, for example, not less than 15 μm and not more than 45 μm. The thickness of the metal layer is, for example, not less than 0.1 μm and not more than 2 μm.

[0038] The conductive member 9 is bonded to the insulating member 1 via the metallization layer 12 and the metal layer by a solder such as silver solder (for example, BAg-8, BAg-8A, or BAg-8B).

[0039] like Figure 3 As shown, the inner wall surface of the through hole 4 formed with the metallization layer 12 includes: an inclined surface 13A, the width (interval) between the inner walls facing each other gradually increases from the inner periphery toward the outer periphery of the insulating member 1; and a vertical surface 13B, which is located on the inner periphery side of the insulating member 1 and has a constant width between the inner walls facing each other. The inclined surface 13A and the vertical surface 13B can be provided over the entire length of the through hole 4.

[0040] Thus, since the inner wall surface of the through hole 4 has the inclined surface 13A, the stress remaining in the insulating member 11 does not increase excessively even if heating and cooling are repeated, and cracks in the insulating member 11 can be suppressed for a long time. Figure 3 ) may be greater than 12° and less than 20°. When the angle θ1 is within this range, the mechanical strength of the insulating member 1 can be maintained, and cracks in the insulating member 1 can be further suppressed. In addition, when measuring the angle θ1 formed by the opposing inner walls, it is sufficient to measure in a cross section perpendicular to the axial direction.

[0041] On the other hand, since a vertical surface 13B is formed on the inner peripheral side of the insulating component 1, it is possible to prevent a gap from being generated between the side surface of the conductive component 9 and the metallization layer 12 formed on the inner wall surface due to deviation in the angle of the inclined surface 13A, thereby improving the airtightness between the conductive component 9 and the insulating component 1 and improving the overall airtightness of the electromagnetic field control component 100.

[0042] The air tightness of the electromagnetic field control member 100 is, for example, 1.3×10 - 11 Pa·m 3 / s or less.

[0043] At least one of the two end faces forming the through hole 4 may have Figure 4 The second inclined surface 22B extending toward both ends in the axial direction and the second vertical surface 22A perpendicular to the central axis in the cross-sectional view shown in the figure. The angle θ2 of the second inclined surface 22A with respect to the second vertical surface 22B is, for example, not less than 4° and not more than 12°.

[0044] like Figure 3 As shown, the volume between the mutually opposed inclined surfaces 13A can be larger than the volume between the mutually opposed vertical surfaces 13B. If the volume between the inclined surfaces 13A is larger, the electromagnetic field control member 100 maintains airtightness, and the volume of the entire opening 10 becomes larger, so even if heating and cooling are repeated, the thermal stress remaining in the insulating member 1 can be further reduced.

[0045] In addition, the volume between the inclined surfaces 13A and the volume between the vertical surfaces 13B do not include the volumes of the blades 14, 15 and the blade connecting member 16 that constitute the first power supply terminal 5 and the second power supply terminal 6 described later, and the volume of the space below the screw inserted into the hole 16a in the center of the blade connecting member 16.

[0046] Inclined surface 13A and vertical surface 13B may be continuous. Inclined surface 13A and vertical surface 13B are continuous when the vertical surface 13B side edge of inclined surface 13A and the inclined surface 13A side edge of vertical surface 13B are connected in appearance, and there may be pores or tiny gaps on the boundary line between the two.

[0047] If the inclined surface 13A and the vertical surface 13B are continuous, the formed metallization layer 12 is less likely to have a discontinuous portion, and the concern of the generation of particles that separate from these surfaces and float through the discontinuous portion can be reduced.

[0048] like Figure 3As shown, the first power supply terminal 5 is inserted into the opening 10 along the radial direction of the insulating member 1, and the bottom is in contact with the conductive member 9. In other words, the first power supply terminal 5 is vertically arranged on the conductive member 9. The rear end of the first power supply terminal 5 is connected to the wire 8, and both contain copper (for example, oxygen-free copper (for example, alloy number C1020 specified in JIS H 3100: 2012 or alloy number C1011 specified in JIS H 3510: 2012, etc.).

[0049] like Figure 3 as well as Figure 4 ( Figure 2A As shown in the enlarged view of the S part of FIG. 1 , the first power supply terminal 5 includes two blades 14 and 15 and a blade connecting member 16. Specifically, as Figure 5 As shown, parts of two blades 14 and 15 are respectively inserted into gaps 19 and 19 on both sides of an H-shaped blade connection member 16 in plan view, and the screw insertion holes 17 and 18 are communicated with each other, and the blades 14 and 15 are connected by bolts (not shown).

[0050] The first power supply terminal 5 is electrically connected to the wire 8 by tightening the front end of the wire 8 to the hole 16a in the center of the blade connecting member 16. Figure 3 as well as Figure 4 As shown, a groove 20 is formed in a given range along the axial direction of the insulating member 1 on the surface of the through hole 4 of the conductive member 9. The lower ends of the blades 14 and 15 are inserted into the groove 20, and the first power supply terminal 5 is erected on the conductive member 9.

[0051] The second power supply terminal 6 shown in FIG. 1 and FIG. 2 is the same as the first power supply terminal 5 , and therefore the same components are denoted by the same reference numerals and their description is omitted.

[0052] The two end surfaces of each groove 20 located on the left and right sides in the axial direction are preferably curved surfaces extending in the axial direction in a plan view. If the two end surfaces of the groove 20 are in such a shape, the thermal stress of the conductive member 9 remaining near the two end surfaces of the groove 20 can be reduced even if heating and cooling are repeated.

[0053] The outer peripheral sides of both end portions of the insulating member 1 may include flat surfaces 1 a on the extension lines of the through-hole 4 in the axial direction.

[0054] The plane 1 a is, for example, a D-shaped cut surface, which is a surface obtained by removing the outer peripheral surface on the extension line of the axial direction of the through hole 4 .

[0055] If the flat surface 1 a is provided, the insulating member 1 can be fixed without rolling during the assembly operation of the first power supply terminal 5 and the second power supply terminal 6 to the conductive member 9 , so that assembly becomes easy.

[0056] The insulating member 1 has electrical insulation and nonmagnetism, and is made of, for example, ceramics mainly composed of aluminum oxide or zirconium oxide, and is particularly preferably made of ceramics mainly composed of aluminum oxide. The average grain size of aluminum oxide crystals is preferably 5 μm or more and 20 μm or less.

[0057] When the average grain size of the aluminum oxide crystals is within the above range, the area of ​​the grain boundary phase per unit area is reduced compared to the case where the average grain size is less than 5 μm, so the thermal conductivity is improved. On the other hand, compared to the case where the average grain size exceeds 20 μm, the area of ​​the grain boundary phase per unit area is increased, so the anchoring effect of the metallization layer 12 in the grain boundary phase increases the adhesion of the metallization layer 12, so the reliability is improved, and the mechanical properties are improved.

[0058] To measure the particle size of aluminum oxide crystals, first, the average particle size D 50 The first grinding is performed from the surface of the insulating member 1 to the depth direction using a copper disk with diamond abrasive grains having an average grain size D 50 The second grinding is performed with a tin plate using diamond abrasive grains of 0.5 μm. The grinding depth is 0.6 mm for example, the sum of the first grinding and the second grinding. The ground surface obtained by these grindings is heat-treated at 1480° C. until the grains and the grain boundary layer can be identified, thereby obtaining an observation surface. The heat treatment is performed for about 30 minutes, for example.

[0059] The heat-treated surface is observed with an optical microscope, for example, by taking an image at a magnification of 400 times. In the image taken, an area of ​​4.8747×10 2 The measurement range is a range of μm. The particle size of each crystal can be obtained by analyzing the measurement range using image analysis software (eg, Win ROOF manufactured by Mitani Shoji Co., Ltd.). The average particle size of the crystal is the arithmetic average of the particle sizes of the individual crystals.

[0060] At this time, the peak value of the particle size of the aluminum oxide crystals may be greater than 0. Thus, the deviation of the particle size of the crystals is suppressed, and thus the concern of local reduction in mechanical strength is reduced. In particular, the peak value of the particle size of the aluminum oxide crystals may be greater than 0.1.

[0061] Kurtosis is generally a statistic that indicates how much a distribution deviates from a normal distribution, and indicates the sharpness of a peak and the extent of a foothill. When the kurtosis is less than 0, the peak is slow and the foothill is short. When it is greater than 0, it means that the peak is sharp and the foothill is long. In a normal distribution, the kurtosis is 0. The kurtosis can be calculated by using the particle size of the crystal using the function Kurt in Excel (registered trademark, Microsoft Corporation). In order to make the kurtosis greater than 0, for example, the particle size of the aluminum oxide powder used as the raw material can be made to have a kurtosis greater than 0.

[0062] Here, a ceramic with aluminum oxide as the main component refers to a ceramic in which the content of aluminum oxide converted into Al2O3 is 90% by mass or more in 100% by mass of all the components constituting the ceramic. As a component other than the main component, for example, at least one of silicon oxide, calcium oxide and magnesium oxide may be included. A ceramic with zirconium oxide as the main component refers to a ceramic in which the content of zirconium oxide converted into ZrO2 is 90% by mass or more in 100% by mass of all the components constituting the ceramic. As a component other than the main component, for example, yttrium oxide may also be included.

[0063] Here, the components constituting the ceramic can be identified based on the measurement results of an X-ray diffraction device using CuKα rays, and the content of each component can be determined by, for example, an ICP (Inductively Coupled Plasma) emission spectrometer or a fluorescent X-ray analyzer.

[0064] The size of the insulating member 1 is set, for example, to an outer diameter of 35 mm to 45 mm, an inner diameter of 25 mm to 35 mm, and an axial length of 340 mm to 420 mm.

[0065] In the case of obtaining an insulating component 1 containing ceramic whose main component is aluminum oxide, first, aluminum oxide powder as the main component, powders of magnesium hydroxide, silicon oxide and calcium carbonate and a dispersant for dispersing the aluminum oxide powder as needed are pulverized and mixed by a ball mill, a bead mill or a vibration mill to form a slurry, a binder is added to the slurry, mixed, and then spray-dried to form particles containing aluminum oxide as the main component.

[0066] In order to make the kurtosis of the particle size of the aluminum oxide crystals 0 or more, the time of pulverization and mixing is adjusted so that the kurtosis of the particle size of the powder becomes 0 or more.

[0067] Here, the average particle size (D 50 ) is greater than 1.6 μm and less than 2.0 μm, and in the total 100 mass % of the above-mentioned powders, the content of magnesium hydroxide powder is 0.43-0.53 mass %, the content of silicon oxide powder is 0.039-0.041 mass %, and the content of calcium carbonate powder is 0.020-0.022 mass %.

[0068] Next, the pellets obtained by the above method are filled into a molding die, and a hydrostatic press molding method (rubber press method) or the like is used, for example, at a molding pressure of 98 MPa or more and 147 MPa or more to obtain a molded body.

[0069] After molding, the elongated lower holes that become a plurality of through holes 4 along the axial direction of the insulating member 1 and the lower holes that open the end faces on both sides along the axial direction of the insulating member 1 are formed by cutting, and both are made into a cylindrical molded body.

[0070] The molded body formed by cutting is heated in a nitrogen atmosphere for 10 to 40 hours as necessary, maintained at 450 to 650° C. for 2 to 10 hours, and then naturally cooled to eliminate the binder and obtain a degreased body.

[0071] Then, regarding the molded body (degreased body), the sintering temperature is set to, for example, 1500°C to 1800°C in an atmospheric atmosphere, and the sintering temperature is maintained for 4 hours to 6 hours, thereby obtaining an insulating component comprising ceramic with alumina as the main component and an average particle size of alumina crystals of 5 μm to 20 μm.

[0072] An embodiment of the electromagnetic field control member of the present disclosure has been described above, but the present disclosure is not limited to this embodiment, and various changes and improvements can be made. For example, direct brazing can be performed without using a metallized layer as needed.

[0073] -Explanation of symbols-

[0074] 1 Insulation components

[0075] 2 Flange

[0076] 3 Axis

[0077] 4 Through holes

[0078] 5 First power supply terminal

[0079] 6 Second power supply terminal

[0080] 7, 8 lines

[0081] 9 Conductive components

[0082] 10 Opening

[0083] 11. Space

[0084] 12 Metallization layer

[0085] 13A Inclined surface

[0086] 13B Vertical plane

[0087] 14, 15 blades

[0088] 16 Blade connecting member

[0089] 17, 18 Screw insertion holes

[0090] 19 Gap

[0091] 20 slots

[0092] 21a, 21b Sleeve

[0093] 22A Second inclined surface

[0094] 22B Second vertical plane

[0095] 100 Components for electromagnetic field control.

Claims

1. An electromagnetic field control component, comprising: The insulating member is made of cylindrical ceramic and has a plurality of through holes extending in the axial direction; a conductive member made of metal and blocking the through hole so as to have an opening portion opened at the outer periphery of the insulating member; a power supply terminal connected to the conducting member, The inner wall surface of the through hole includes: an inclined surface, where the width between the inner walls facing each other gradually increases from the inner periphery toward the outer periphery of the cylindrical insulating component; and a vertical surface, which is located on the inner periphery side of the insulating component and has a constant width between the inner walls facing each other.

2. The electromagnetic field control member according to claim 1, wherein: The volume between the mutually opposing inclined surfaces is larger than the volume between the mutually opposing vertical surfaces.

3. The electromagnetic field control member according to claim 1 or 2, wherein: The inclined surface is continuous with the vertical surface.

4. The electromagnetic field control member according to claim 1 or 2, wherein: The conductive member is disposed at a position in the through hole where the vertical surface is located, and blocks the through hole.

5. The electromagnetic field control member according to claim 1 or 2, wherein: A metallization layer or a plating layer is formed on the inner wall surface of the through hole. The metallization layer or the plating layer is fixed to the side surface of the conductive member in an airtight state.

6. The electromagnetic field control member according to claim 1 or 2, wherein: The conductive member has a groove in the thickness direction for mounting the power supply terminal. Both end surfaces of the groove are curved surfaces extending in the axial direction in a plan view.

7. The electromagnetic field control member according to claim 1 or 2, wherein: The outer peripheral sides of both ends of the insulating member include flat surfaces on the extension lines of the through-hole in the axial direction.

8. The electromagnetic field control member according to claim 1 or 2, wherein: The insulating member includes ceramics containing aluminum oxide as a main component, and an average grain size of aluminum oxide crystals is 5 μm or more and 20 μm or less.

9. The electromagnetic field control member according to claim 8, wherein: The kurtosis of the particle size of the aluminum oxide crystals is 0 or more.

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