JP5755167B2 - Internal masking method of chamber pipe in positron accelerator - Google Patents

Description

The present invention, for masking a predetermined range of the inner surface of the chamber pipe in positron accelerator, it relates to the inner surface masking process chamber pipe in positron accelerator.

  A positron accelerator for accelerating positrons includes a vacuum chamber configured in an annular shape having a diameter of about 1 km, for example, by connecting a number of tubular chamber pipes made of metal such as aluminum or copper. It is a device that imparts high energy to positrons by evacuating the interior of the chamber to a high vacuum and accelerating the positrons around the chamber by an electromagnetic field to accelerate them to near the speed of light.

  In such a positron accelerator, in order to suppress the emission of photoelectrons and secondary electrons that cause instability of positrons in the vacuum chamber, a fine groove (groove) along the longitudinal direction of the pipe is formed on the inner surface of each chamber pipe. Processing and forming are performed, or as disclosed in Patent Document 1, the inner surface of the chamber pipe is roughened by blasting.

  In the blasting method for a vacuum chamber disclosed in Patent Document 1, a traveling carriage having an injection nozzle is brought into contact with a predetermined position on the inner surface of the chamber pipe so that only a predetermined portion of the inner surface of the chamber pipe can be blasted. It is configured to travel through the traveling roller and the guide roller, and to always spray fine particles from a spray nozzle of the traveling carriage toward a predetermined portion of the inner surface of the chamber pipe, and to blast only a predetermined portion. .

Japanese Patent No. 3825448

  However, when the groove is processed and formed on the inner surface of the chamber pipe, the groove is processed first, and then the above blasting and pipe processing are performed. There is a problem that foreign matters such as cutting scraps are stuck in the gaps between the fine grooves and remain, making it difficult to remove them. In particular, in the case of a long chamber pipe, it is difficult to remove the foreign matter remaining in the deep part of the pipe that cannot be reached, and even if it can be removed, there is a concern that the inner surface of the pipe may be damaged. Even if only the groove portion is to be masked, a masking member such as a tape cannot be applied to the inner surface of the long chamber pipe, and it is impossible to perform masking substantially.

The present invention has been made in view of the above problems, by simple and inexpensive construction, it can be easily masked only Teihan circumference at the chamber pipe inner surface, providing an inner surface masking method of the chamber pipe in positron accelerator The purpose is to do.

In order to solve the above problems, the present invention employs the following means.
That is, the first aspect of the inner surface masking process chamber pipe in positron accelerator according to the present invention, the range of the groove formed on the inner surface of the chamber pipe constituting the vacuum chamber in positron accelerator and masking range, masking this range In addition, after flowing a masking agent in which fats and oils that solidify at room temperature are dissolved, a masking process for coagulating the masking agent to mask the masking range and a processing process for the inner surface of the chamber pipe are completed. Later, the chamber pipe is heated from the outer surface, the solidified masking agent is dissolved and removed from the masking range, and the remaining components of the masking agent adhering to the inner surface of the chamber pipe are cleaned. And a cleaning step.

According to the above masking method, in the masking process, the masking agent heated and liquefied is poured into the groove area on the inner surface of the chamber pipe , and then the masking agent is solidified at room temperature to ensure the masking range. Can be masked. In the removing step, the masking agent can be easily removed by dissolving the masking agent solidified by heating the chamber pipe from the outer surface. For this reason, it is possible to easily mask only the groove range of the chamber pipe , which has been difficult in the past, with a simple and inexpensive configuration.
In addition, the masking agent that has been liquefied by heating flows into the concave / convex shape within the groove and completely masks the concave / convex shape, ensuring that foreign matter generated in the next process bites into the concave / convex portion. Can be prevented.
In order to suppress the emission of photoelectrons and secondary electrons that cause instability of positrons, the inner surface of the chamber pipe constituting the vacuum chamber in the positron accelerator is subjected to blasting after a fine groove is formed along the longitudinal direction of the pipe. The inner surface is roughened by applying the masking method according to the present invention before the blasting process, so that the grooved area is masked reliably and easily, and the blasting process is performed. It is possible to prevent the fine particles from remaining in the gaps between the grooves.

Further, the second aspect of the method for masking the inner surface of the chamber pipe in the positron accelerator according to the present invention is the first aspect, wherein in the removing step, the chamber pipe is held with the masking range on the upper side, and heating the masking range from outside the chamber pipe, the masking agent is solidified, the by dissolving only the vicinity of the interface with the chamber pipe, stripped from the masking range for the majority of the masking agent as a solid Then, it is dropped and taken out from the chamber pipe .

According to the masking method described above, the masking agent is dissolved by dissolving only the vicinity of the interface with the chamber pipe of the masking agent that has solidified without dissolving all the masking agent that has solidified over the masking range. Since most of the solid can be taken out from the chamber pipe , it is easy to remove the masking agent and to post-process the used masking agent.
Moreover, foreign substances adhering to the surface of the masking agent during the processing of the inner surface and the end surface of the chamber pipe, because they are removed from the chamber pipe with solid masking agents, reliably prevent the foreign matter from adhering again masking range can do.

A third aspect of the method for masking the inner surface of a chamber pipe in a positron accelerator according to the present invention is the first or second aspect, wherein in the masking step, the chamber pipe is placed with the masking range on the lower side. After holding and placing the solid masking agent inside the chamber pipe and on the masking area at a predetermined interval, the chamber pipe is heated from the outer surface to dissolve the solidified masking agent. It is made to flow in the said masking range, and it is made to solidify.

According to the above masking method, when the masking agent is supplied to the inside of the chamber pipe , the masking agent is in a solid state, so that it is easier to handle than in the case where the masking agent is in a liquid state. The masking agent can be prevented from adhering and the masking operation can be facilitated.

The fourth aspect of the inner surface masking process chamber pipe in positron accelerator according to the present invention, the in the first third or aspects, in the washing step, slightly etching the inner surface of the chamber pipe Thus, the residual component of the masking agent is chemically washed.

According to the above masking method, by appropriately selecting an etching agent according to the material of the chamber pipe and the masking agent, the remaining components of the masking agent are completely removed while minimizing the etching amount of the chamber pipe. be able to.

Moreover, the 5th aspect of the inner surface masking method of the chamber pipe in the positron accelerator which concerns on this invention uses solid paraffin as said masking agent in any one of said 1st to 4th aspect, It is characterized by the above-mentioned.

  Thus, by using solid paraffin as the masking agent, the masking agent can be made inexpensive, the melting point of the masking agent can be lowered, and the masking agent can be easily applied and removed.

As described above, according to the inner surface masking process chamber pipe in positron accelerator according to the present invention, by simple and inexpensive construction, it can be easily masked only Teihan circumference at the chamber pipe inner surface.

The present onset bright is a longitudinal sectional view of the applicable switch Yanbapaipu. It is the II section enlarged view of FIG. It is process drawing which shows one Embodiment of this invention, (a) is a longitudinal cross-sectional view which shows the state by which the liquid masking agent was poured into the chamber pipe in the masking process, (b) is a masking agent coagulating in a masking process (C) is a longitudinal cross-sectional view which shows a removal process, (d) is a longitudinal cross-sectional view which shows a washing | cleaning process. The other embodiment of a masking process is shown, (a) is a longitudinal cross-sectional view which shows the state by which the solid masking agent has been arrange | positioned inside a chamber pipe , (b) is the state which the masking agent of (a) melt | dissolved. It is a longitudinal cross-sectional view shown.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
Figure 1 is a longitudinal sectional view of a chamber pipe 1 of the inner surface masking methods available positive electron accelerator apply chamber pipe according to the present invention. The chamber pipe 1 is formed by extruding an aluminum alloy material, for example, and has a length of about 3 to 5 meters. The chamber pipe 1 includes a straight pipe and a loosely curved pipe, and these chamber pipes 1 are connected in an annular shape to form a positron accelerator vacuum chamber having a diameter of about 1 km and a circumference of about 3 km, for example. . The inside of the vacuum chamber is set to a high vacuum of about 1 × 10 ⁻⁸ Torr, and the positron travels around the inside by an electromagnetic field and is accelerated to near the speed of light, thereby giving high energy to the positron.

  A chamber pipe 1 shown in FIG. 1 constitutes a curved portion of a vacuum chamber, and a rectangular-shaped radiation light channel 3 extends horizontally on both sides of a circular-shaped beam channel 2 where a positron circulates. Is formed. A cooling water channel 5 through which cooling water circulates is formed outside the inner end face 4 of the radiation light channel 3. The chamber pipe 1 constituting the straight portion of the vacuum chamber is not provided with the radiated light channel 3 but has a circular cross section of only the beam channel 2. The thickness of the beam channel 2 is, for example, 6 mm, and the inner diameter of the beam channel 2 is, for example, 90 mm. The dimension from one inner end face 4 of the radiated light channel 3 to the other inner end face 4 is, for example, 220 mm, and the facing distance between the upper surface and the lower surface of the radiated light channel 3 is, for example, 14 mm.

  When a trajectory is bent while high-energy positrons close to the speed of light are passing through the magnetic field in the beam channel 2 of the curved chamber pipe 1, radiant light is generated in the tangential direction of the trajectory. 3 is irradiated to the inner end face 4. Since the inner end surface 4 is heated at that time, the heat is cooled by the cooling water flowing through the cooling water channel 5. This prevents a thermal load from being applied to the inner surface of the chamber pipe 1 (beam channel 2), and also interferes with the positrons that circulate due to the release of photoelectrons due to the photoelectric effect associated with the irradiation of the radiated light. The problem of becoming stable is avoided.

  As shown in FIG. 2 in an enlarged manner, a plurality of grooves 7 (grooves) are formed on the upper and lower surfaces of the inner surface of the chamber pipe 1 along the longitudinal direction of the pipe. This groove 7 is provided in order to suppress the probability that the photoelectrons emitted inside the chamber pipe 1 return to the beam side due to the limitation due to the surface shape. For the same reason, the inner end face 4 of the radiation channel 3 is blasted and roughened. The groove 7 is formed simultaneously with the extrusion of the chamber pipe 1. The blasting process of the inner end face 4 is performed by a dedicated blasting apparatus (not shown) configured to be able to travel inside the chamber pipe 1. After completion of this blasting process, the bending of the chamber pipe 1 and other machining are performed.

  When blasting the inner end face 4 or performing other machining operations, a large amount of foreign matter such as fine particles to be blasted and cutting waste accompanying pipe processing is generated. In order to prevent it from biting into and remaining in the gap between the grooves 7 on the inner surface, that is, the groove 7, a width range slightly wider than the width on which the groove 7 is formed is defined as a masking range M, The masking process is performed by the masking method according to the present invention. The masking method according to the present invention includes a masking step A, a removing step B, and a cleaning step C. Below, each process AC is demonstrated in order based on Fig.3 (a)-(d).

[Masking process A]
In the masking step A, first, as shown in FIG. 3A, the chamber pipe 1 is held horizontally so that one of the upper and lower grooves 7 (masking range M) faces directly below, and solidifies therein at room temperature. Oils and fats, for example, solid paraffin having a melting point of about 70 ° C. heated and dissolved in a liquid state are poured as a masking agent. The injection amount of the liquid solid paraffin 8 is such that the lower groove 7 is completely submerged below the liquid surface (the height of the liquid surface 8a in FIG. 2). At this time, it is necessary to cover the openings at both ends of the chamber pipe 1 to a position higher than the line 8a so that the liquid solid paraffin 8 does not flow outside. Then, the solid paraffin 8 is naturally cooled and solidified. When the solid paraffin 8 is solidified, the chamber pipe 1 is reversed, and the masking range M on the opposite side is similarly masked as shown in FIG.

  When the masking of the upper and lower masking ranges M is completed, blasting of the inner surface (inner end surface 4) of the chamber pipe 1, other machining, bending of the chamber pipe 1, and the like are performed. Foreign matters such as blast fine particles and cutting waste generated at that time do not adhere to the groove 7 masked by the solid paraffin 8. Therefore, foreign matter does not bite into the gap between the grooves 7 and remain. Since the solid paraffin 8 is flexible even when solidified and the curvature of the chamber pipe 1 is shallow, the chamber pipe 1 is masked with the solid paraffin 8 and then bent. Even if it performs, solid paraffin 8 does not crack or peel. When various processing of the chamber pipe 1 is completed, the foreign matter accumulated inside the chamber pipe 1 is removed by water flow cleaning, air blow, or the like.

[Removal step B]
When the foreign matter removal is completed, the process proceeds to a removal step B. In the removal step B, the chamber pipe 1 is held horizontally so that one of the upper and lower grooves 7 (masking range M) faces directly upward, and the upper surface of the beam channel 2 of the chamber pipe 1 is exposed from the outside with a burner (not shown) or the like. By heating to a temperature higher than the melting point of the solid paraffin 8 (for example, about 90 to 100 ° C.), only the vicinity of the interface of the upper solid paraffin 8 solidified with the beam channel 2 (masking range M) is dissolved. Thereby, as shown in FIG.3 (c), the coupling | bonding of the upper solid paraffin 8 and the masking range M is released, and most of the solid paraffin 8 peels from the masking range M, and it falls. The solid solid paraffin 8 dropped in this way is taken out from the opening at one end of the chamber pipe 1 and taken out. Thereafter, the chamber pipe 1 is reversed, and the solid paraffin 8 masking the opposite groove 7 (masking range M) is peeled off in the same manner and taken out from the chamber pipe 1.

  Instead of dissolving only the vicinity of the interface of the solid paraffin 8 with the chamber pipe 1 and taking out most of the solid paraffin 8 to the outside in the solid state, the entire chamber pipe 1 is more than the melting point of the solid paraffin 8. It may be heated to a sufficiently high temperature, and the solid paraffin 8 fixed in the upper and lower masking ranges M may be completely dissolved at the same time to be made into a liquid and flowed out from the chamber pipe 1. However, in this case, since the liquid solid paraffin 8 may adhere to unnecessary portions other than the masking range M, the number of steps in the next cleaning step C may increase.

[Washing process C]
When the extraction of the solid paraffin 8 is completed as described above, the process proceeds to the cleaning step C. In the cleaning process C, first, the inside of the chamber pipe 1 is cleaned with hot water and a water-soluble neutral detergent, and the inner surface of the chamber pipe 1 is slightly etched as shown in FIG. The remaining components of the solid paraffin 8 adhering to the inner surface of the substrate are chemically cleaned. When the material of the chamber pipe 1 is an aluminum alloy, for example, an aqueous sodium hydroxide solution is used as the etchant. The etching amount may be about 1 micron, for example. Thereby, the residual component of the solid paraffin 8 adhering to the inner surface of the chamber pipe 1 can be completely removed. Note that other etching agents may be used depending on the material of the chamber pipe 1.

As described above, the method for masking the inner surface of the chamber pipe in the positron accelerator according to the present invention heats and dissolves the solid paraffin 8 that solidifies at room temperature, and uses this as a masking agent to flow into the masking range M on the inner surface of the chamber pipe 1. Then, after the solid paraffin 8 is solidified to complete the masking step A for masking the masking range M and the inner surface processing step of the chamber pipe 1, the chamber pipe 1 is heated from the outer surface to solidify the solid paraffin. 8 includes a removal process B for dissolving 8 from the masking range M and a cleaning process C for cleaning residual components of the solid paraffin 8 adhering to the inner surface of the masking range M.

  According to this masking method, in the masking step A, the masking range M can be reliably masked by pouring the solid paraffin 8 liquefied by heating onto the masking range M to be solidified. Moreover, in the removal process B, if the chamber pipe 1 is heated from the outer surface and the solid paraffin 8 solidified is dissolved, this can be easily removed. For this reason, with a simple and inexpensive configuration, it is possible to easily mask only a predetermined range of the inner surface of the chamber pipe 1, which has been difficult in the past.

  Further, in the removing step B, the chamber pipe 1 is held with the masking range M on the upper side, and the masking range M is heated from the outside of the chamber pipe 1 to solidify the solid paraffin 8 solidified with the chamber pipe 1. By dissolving only the vicinity of the interface, most of the solid paraffin 8 is solid and peeled off from the masking range M and then dropped and taken out from the chamber pipe 1. Thus, most of the solid paraffin 8 can be taken out from the chamber pipe 1 in a solid state, so that the removal of the solid paraffin 8 and the post-treatment of the used solid paraffin 8 are facilitated. In addition, since the foreign matter adhering to the surface of the solid paraffin 8 during the blasting process of the inner surface of the chamber pipe 1 is taken out from the chamber pipe 1 together with the solid solid paraffin 8, this foreign matter is again masked. Adherence to M can be reliably prevented.

  Further, in the cleaning step C, the inner surface of the chamber pipe 1 is slightly etched so that the remaining components of the masking agent such as the solid paraffin 8 are chemically cleaned. Therefore, depending on the material of the chamber pipe 1 and the masking agent. By appropriately selecting an etching agent, the masking agent can be completely removed while minimizing the etching amount of the chamber pipe 1.

  In the above-described embodiment, the groove 7 portion that is an unevenly processed portion formed to suppress the emission of photoelectrons and secondary electrons that cause instability of positrons on the inner surface of the chamber pipe 1 constituting the vacuum chamber in the positron accelerator. Is set to the masking range M, and the solid paraffin 8 that has been heated and liquefied is poured into the masking area M for masking. For this reason, it is possible to reliably prevent foreign matters such as fine particles in the next blasting process from biting into the gaps between the grooves 7 and remaining, and to easily blast the inner surface of the chamber pipe 1 having the grooves 7. Can do.

  Moreover, by using the solid paraffin 8 as a masking agent, the masking agent can be made inexpensive, the melting point as the masking agent can be lowered, and the masking agent can be easily applied and removed.

[Other Embodiments of Masking Step A]
FIG. 4 shows a masking step A ′ which is another embodiment of the masking step A.
First, as shown in FIG. 4A, the chamber pipe 1 is held horizontally so that one of the upper and lower grooves 7 (masking range M) faces directly below, and a solid state is formed on the inside and on the masking range M. The blocks of solid paraffin 8 are placed at predetermined intervals. As shown in FIG. 2, when the solid paraffin 8 is dissolved and liquefied, the size and arrangement interval of the blocks of the solid paraffin 8 are such that the lower groove 7 is completely submerged below the liquid surface. Set in advance.

  Next, the chamber pipe 1 is heated from the outer surface, and the solid paraffin 8 that has been solidified is dissolved and spread over the masking range M as shown in FIG. Then, the solid paraffin 8 is naturally cooled and solidified. When the solid paraffin 8 is solidified, the chamber pipe 1 is reversed and the masking range M on the opposite side is similarly masked. When the masking range M on the opposite side is masked, it is necessary to take care not to dissolve the previously masked solid paraffin 8 when the chamber pipe 1 is heated.

  According to this masking step A ′ method, when the solid paraffin 8 is supplied into the chamber pipe 1, the solid paraffin 8 is in a solid state, so that it is easier to handle than when the solid paraffin 8 is in a liquid state. The solid paraffin 8 can be reliably prevented from adhering to unnecessary portions, and the masking operation can be facilitated.

It should be noted that the present invention is not limited to the configuration of the above embodiment, and can be appropriately modified or improved without departing from the gist of the present invention. The form is also included in the scope of the right of the present invention.
For example, the pipe member for masking does not necessarily have to be a chamber pipe constituting a vacuum chamber of a positron accelerator, and may be another type of pipe member.
Moreover, although it is suitable to use the solid paraffin 8 as a masking agent, it is not limited only to the solid paraffin 8, You may use other fats and oils as a masking agent. Furthermore, as a modification, it may be possible to use other substances (low melting point metals, etc.) that solidify at room temperature and liquefy at a temperature of about 60 ° C. to 120 ° C. as a masking agent, even if they are not fats and oils.

1 Chanbapai flop 7 glue Bed <br/> 8 solid paraffin (masking agent)
A, A 'Masking process B Removal process C Cleaning process M Masking range

Claims (5)

After the range of the groove formed on the inner surface of the chamber pipe constituting the vacuum chamber in positron accelerator and masking range and the masking range of this and flushed with masking agent dissolved by heating the fats and oils to coagulate at room temperature, A masking step of coagulating the masking agent to mask the masking range;
After the processing of the inner surface of the chamber pipe is completed, the removal step of heating the chamber pipe from the outer surface, dissolving the solidified masking agent and removing it from the masking range;
A cleaning step of cleaning residual components of the masking agent adhering to the inner surface of the chamber pipe ;
A method for masking the inner surface of a chamber pipe in a positron accelerator, comprising : In the removing step, holding the chamber pipe with the masking range on the upper side, heating the masking range from the outside of the chamber pipe , and solidifying the masking agent near the interface with the chamber pipe by dissolving only the majority of the masking agent after peeling from the masking range in solid form, the chamber pipe in positron accelerator according to claim 1, characterized in that removal from the chamber pipe by dropping it Internal masking method. In the masking step, holding the chamber pipe with the masking range on the lower side, and after placing the solid masking agent on the inside of the chamber pipe and on the masking range at a predetermined interval, 3. The method for masking an inner surface of a chamber pipe in a positron accelerator according to claim 1, wherein the chamber pipe is heated from the outer surface, the solidified masking agent is dissolved and allowed to flow into the masking range to be solidified. . Wherein in the cleaning step, the chamber pipe in positron accelerator according to any one of claims 1 to 3, characterized by chemically cleaning the residual components of the masking agent by slightly etching the inner surface of the chamber pipe Internal masking method.   5. The method for masking an inner surface of a chamber pipe in a positron accelerator according to claim 1, wherein solid paraffin is used as the masking agent.

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