JP2004259528A - Vacuum chamber for particle accelerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum chamber for a particle accelerator well controlling a charged particle by preventing a non-magnetic conductor layer in the chamber from generation of local defects. <P>SOLUTION: The vacuum chamber for a particle accelerator comprises a cylindrical ceramic member 1 having conductor layers arranged so as to extend over both end surfaces and an inner peripheral surface, cylinder-shaped metallic members 6 brazed to the conductor layers at the both end surfaces of the ceramic member 1, coaxially with the ceramic member, respectively, and the non-magnetic conductor layer 5 covering a whole inner surface of the ceramic member 1 and the metallic member 6. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vacuum chamber for a particle accelerator for accelerating and deflecting charged particles such as electrons and heavy particles by a high-frequency or pulsed electromagnetic field.
[0002]
[Prior art]
FIG. 2 shows a conventional vacuum chamber for a particle accelerator. FIG. 2 is a sectional view of a vacuum chamber for a particle accelerator. In FIG. 2, reference numeral 11 denotes a cylindrical ceramic member which is electrically insulating and made of a non-magnetic material, and the inside of which is charged when accelerating or deflecting charged particles such as electrons and heavy particles by a high frequency or pulsed electromagnetic field. Acts as a vacuum space that orbits particles.
[0003]
Reference numeral 16 denotes a cylindrical metal member brazed to both end surfaces of the ceramic member 11, such as an iron (Fe) -nickel (Ni) -cobalt (Co) alloy or an iron (Fe) -nickel (Ni) alloy. The inside thereof forms a vacuum space, and the vacuum space is continuously formed by connecting the end opposite to the joint surface with the ceramic member 11 to another vacuum vessel or vacuum component.
[0004]
Reference numeral 17 denotes a conductor layer in which a Ni plating layer is deposited on the surface of a molybdenum (Mo) -manganese (Mn) metallized layer previously deposited on the end face of the ceramic member 11. And the metal member 16 are joined via the brazing material 18.
[0005]
Reference numeral 15 denotes a nonmagnetic conductor layer formed on the inner peripheral surfaces of the ceramic member 11 and the metal member 16 and is made of a conductive nonmagnetic material such as titanium (Ti) or titanium nitride (TiN).
[0006]
Such a non-magnetic conductor layer 15 is formed by brazing the ceramic member 11 and the metal member 16 and then attaching the ceramic member 11 and the metal member 16 to their inner peripheral surfaces by a vacuum deposition method.
[0007]
When such a vacuum chamber is used in a particle accelerator, charged particles pass near the center of the ceramic member 11. Since the electric field distribution generated at this time is required to be always constant in the charged particle orbital direction, the nonmagnetic conductor layer 15 is continuously coated on the inner peripheral surface of the particle accelerator vacuum chamber so as not to have local defects. It needs to be formed (for example, see Patent Document 1 below).
[0008]
[Patent Document 1]
JP-A-5-275131
[Problems to be solved by the invention]
However, when the ceramic member 11 and the metal member 16 are brazed in the above-described conventional vacuum chamber for a particle accelerator, the brazing material 18 easily projects from the end of the conductor layer 17 to the inside of the ceramic member 11 and protrudes. The protruding portion of the material 18 covers the entire open end of the inner peripheral surface of the ceramic member 11, and the nonmagnetic conductor layer 15 is not formed on the inner peripheral surface of the ceramic member 11 over the entire periphery of the protruding portion of the brazing material 18. There was a problem.
[0010]
Therefore, a portion where the nonmagnetic conductive layer 15 and the conductive layer 17 are not electrically in contact with each other is generated over the entire circumference, and when used in a particle accelerator, the electric field generated by the charged particles and the ceramic member 11 There is a problem that a discharge is generated between the non-magnetic conductor layer 15 and the conductor layer 17 due to a fluctuating magnetic field generated by a magnet provided outside the semiconductor device, which adversely affects the control of charged particles.
[0011]
The present invention has been devised in view of the problems of the related art, and has as its object to prevent the occurrence of local defects in a nonmagnetic conductor layer inside a vacuum chamber for a particle accelerator to prevent charged particles from being generated. The object of the present invention is to provide a vacuum chamber for a particle accelerator having good control of the particle accelerator.
[0012]
[Means for Solving the Problems]
The vacuum chamber for a particle accelerator according to the present invention has a cylindrical ceramic member in which a conductor layer is formed from both end surfaces to an inner peripheral surface, and the conductor layer on both end surfaces of the ceramic member is coaxial with the ceramic member. And a non-magnetic conductor layer attached to the entire surface of the ceramic member and the inner peripheral surface of the metal member.
[0013]
A vacuum chamber for accelerating particles according to the present invention includes a cylindrical ceramic member having conductor layers formed from both end surfaces to an inner peripheral surface, and brazing to the conductor layers on both end surfaces of the ceramic member coaxially with the ceramic member. By providing a cylindrical metal member, and a non-magnetic conductor layer applied to the entire inner peripheral surface of the ceramic member and the metal member, a brazing material for joining the ceramic member and the metal member is formed. The brazing material can be spread over the surface of the conductor layer formed on the inner peripheral surface of the ceramic member so that the brazing material has a smooth surface over the entire periphery without partially protruding inside the ceramic member. Can be. As a result, it is possible to suppress the occurrence of a portion where the nonmagnetic conductor layer and the conductor layer are not electrically in contact with each other locally. Therefore, the nonmagnetic conductor layer is provided outside the ceramic member or the electric field generated by the charged particles. Discharge does not occur locally due to the fluctuating magnetic field generated by the magnet, which does not adversely affect the control of charged particles, and does not adversely affect the magnetic field generated by the magnet. It can be a vacuum chamber for an accelerator.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
The vacuum chamber for a particle accelerator of the present invention will be described in detail below. FIG. 1 is a sectional view showing an example of an embodiment of a vacuum chamber for a particle accelerator according to the present invention. In FIG. 1, 1 is a ceramic member, 5 is a nonmagnetic conductor layer, 6 is a metal member, 7 is a conductor layer, and 8 is a brazing material.
[0015]
The ceramic member 1 of the present invention is made of ceramic such as alumina (Al ₂ O ₃ ) sintered body, silicon nitride (SiN) sintered body, aluminum nitride (AlN) based sintered body, and is electrically insulating. Is a cylindrical body made of the non-magnetic material. The ceramic member 1 has a circular cross section perpendicular to the axial direction, an elliptical shape, an elliptical shape in which both ends of a pair of opposed linear portions are connected by an arc-shaped curve, and the like. Etc. for accelerating charged particles.
[0016]
The metal member 6 is a cylindrical member brazed to both end surfaces of the ceramic member 1 and is made of a metal such as an Fe-Ni-Co alloy or an Fe-Ni alloy. The inside is a vacuum space, and the end opposite to the joining surface with the ceramic member 1 is connected to another vacuum container or vacuum component, so that the ceramic member 1, the metal member 6, the vacuum container And a continuous vacuum space formed by vacuum components.
[0017]
In addition, a conductor layer 7 is formed from both end surfaces of the ceramic member 1 to the inner peripheral surface. The conductor layer 7 is formed of a metallized layer such as Mo-Mn. A Ni plating layer or the like is adhered on the surface of the conductor layer 7 in order to improve the wettability of the brazing material 8 and improve the adhesion with the brazing material 8. Good to be.
[0018]
The nonmagnetic conductor layer 5 is formed on the inner peripheral surfaces of the ceramic member 1 and the metal member 6, and is made of a conductive nonmagnetic material such as Ti or TiN. Such a non-magnetic conductor layer 5 is formed by joining the ceramic member 1 and the metal member 6 with the brazing material 8, and then attaching the ceramic member 1 and the metal member 6 to their inner peripheral surfaces by a vacuum deposition method.
[0019]
The width of the conductor layer 7 on the inner peripheral surface of the ceramic member 1 is preferably 4 to 10 mm. Thereby, the brazing material 8 joining the ceramic member 1 and the metal member 6 can be spread on the surface of the conductor layer 7 formed on the inner peripheral surface of the ceramic member 1, and the brazing material 8 is Can be applied so as to have a gentle surface over the entire circumference without partially protruding. As a result, it is possible to suppress the occurrence of a portion where the non-magnetic conductor layer 5 and the conductor layer 7 are not electrically in contact with each other locally. Discharge does not occur locally due to the fluctuating magnetic field caused by the magnet provided outside, which does not adversely affect the control of charged particles, and does not adversely affect the magnetic field generated by the magnet. And a vacuum chamber for a particle accelerator having a high density.
[0020]
When the width of the conductor layer 7 is smaller than 4 mm, when the ceramic member 1 and the metal member 6 are brazed, the brazing material 8 that has flowed out collects at the end of the conductor layer 7 and easily protrudes inside the ceramic member 1 and protrudes. As a result, the protruding portion of the brazing material 8 covers a part of the opening of the ceramic member 1 so that the nonmagnetic conductor layer 5 is hardly formed on the inner surface of the ceramic member 1. When the width of the conductor layer 7 exceeds 10 mm, the magnetism of the Ni plating layer becomes large and cannot be ignored, and when used in a particle accelerator, the magnetism of the Ni plating layer adversely affects the magnetic field generated by the magnet. Easy to reach.
[0021]
【Example】
An embodiment of the vacuum chamber for a particle accelerator according to the present invention will be described below.
[0022]
The vacuum chamber for a particle accelerator having the configuration of FIG. 1 was manufactured as follows. A cylindrical ceramic member 1 made of an alumina sintered body having a purity of about 99% by weight and made of an electrically insulating nonmagnetic material was prepared. This ceramic member 1 had an inner diameter of 72.7 mm, an outer diameter of 78.5 mm, and a total length of 300 mm.
[0023]
Then, a metal paste obtained by mixing an organic binder and a solvent with Mo powder, Mn powder and silicon oxide (SiO ₂ ) powder in a range of 4 mm from both end surfaces and both end surfaces to the inner peripheral surface of the ceramic member 1 is applied to a thickness of about 10 μm. A metallized layer made of a Mo—Mn alloy was applied to the ceramic member 1 by printing and applying it to a thickness, firing it at a temperature of about 1400 ° C. in a humidified forming gas after drying.
[0024]
Thereafter, a Ni plating layer was applied to a thickness of about 2 μm on the metallized layer by electrolytic plating to form a conductor layer 7.
[0025]
Thereafter, cylindrical metal members 6 were brazed to both end surfaces of the ceramic member 1. The metal member 6 was made of an Fe—Ni—Co alloy, had a cylindrical shape with an inner diameter of 73 mm and an outer diameter of 74.5 mm, and had a length in the axial direction of 15 mm.
[0026]
Then, a foil made of an Ag—Cu alloy as the brazing material 8 was placed at the joint between the ceramic member 1 and the metal member 6, and the entire vacuum chamber for the particle accelerator was heated to 820 ° C. and brazed.
[0027]
Finally, a non-magnetic conductive layer 5 of Ti was formed to a thickness of 5 μm on the inner surfaces of the ceramic member 1 and the metal member 6 by a vacuum evaporation method.
[0028]
The sample produced in this way was used in a particle accelerator, but exhibited the desired performance without any problem and functioned as a component of the accelerator.
[0029]
Next, except that the width of the conductor layer 7 on the inner peripheral surface of the ceramic member 1 was set to 10 mm, a vacuum chamber for a particle accelerator was manufactured in the same manner and used in the accelerator. Functioned as a component of the accelerator.
[0030]
Next, except that the width of the conductor layer 7 on the inner peripheral surface of the ceramic member 1 was set to 3 mm, a vacuum chamber for a particle accelerator was manufactured in the same manner and used in the accelerator, but an electric field generated by charged particles and a ceramic member were used. Discharge occurred locally due to a fluctuating magnetic field generated by a magnet provided outside the device 1, causing a problem in stable control of charged particles.
[0031]
Next, a vacuum chamber for a particle accelerator was manufactured in the same manner except that the width of the conductor layer 7 on the inner peripheral surface of the ceramic member 1 was set to 11 mm, and the vacuum chamber was used in the accelerator. Due to the magnetic field of the conductor layer 7, the fluctuating magnetic field does not act on the charged particles correctly, and stable control of the charged particles becomes difficult.
[0032]
From the above, in the vacuum chamber for a particle accelerator of the present invention, a portion where the nonmagnetic conductor layer 5 and the conductor layer 7 are not electrically in contact with each other is not locally generated, and particularly, the inner periphery of the ceramic member 1 It was found that when the surface conductor layer 7 was 4 to 10 mm, the effect was excellent.
[0033]
It should be noted that the present invention is not limited to the above-described embodiments and examples, and various changes may be made without departing from the spirit of the present invention.
[0034]
【The invention's effect】
A vacuum chamber for accelerating particles according to the present invention includes a cylindrical ceramic member having conductor layers formed from both end surfaces to an inner peripheral surface, and brazing to the conductor layers on both end surfaces of the ceramic member coaxially with the ceramic member. By providing a cylindrical metal member, and a non-magnetic conductor layer applied to the entire inner peripheral surface of the ceramic member and the metal member, a brazing material for joining the ceramic member and the metal member is formed. The brazing material can be spread over the surface of the conductor layer formed on the inner peripheral surface of the ceramic member so that the brazing material has a smooth surface over the entire periphery without partially protruding inside the ceramic member. Can be. As a result, it is possible to suppress the occurrence of a portion where the nonmagnetic conductor layer and the conductor layer are not electrically in contact with each other locally. Therefore, the nonmagnetic conductor layer is provided outside the ceramic member or the electric field generated by the charged particles. Discharge does not occur locally due to the fluctuating magnetic field generated by the magnet, which does not adversely affect the control of charged particles. It can be a vacuum chamber for an accelerator.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an example of an embodiment of a vacuum chamber for a particle accelerator according to the present invention.
FIG. 2 is a sectional view showing a conventional vacuum chamber for a particle accelerator.
[Explanation of symbols]
1: ceramic member 5: nonmagnetic conductor layer 6: metal member 7: conductor layer

Claims (2)

A cylindrical ceramic member having a conductor layer formed from both end surfaces to an inner peripheral surface; and a cylindrical metal member brazed coaxially with the ceramic member to the conductor layers on both end surfaces of the ceramic member. And a non-magnetic conductor layer applied to the entire inner peripheral surface of the ceramic member and the metal member. 2. The vacuum chamber for a particle accelerator according to claim 1, wherein the conductor layer has a width of 4 to 10 mm on an inner peripheral surface of the ceramic member. 3.

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