JPH0722196A - Tandem type accelerator - Google Patents

Abstract

PURPOSE:To construct an inlet canal member light in weight and enhance the cooling efficiency. CONSTITUTION:An inlet canal member 22 is formed as a whole in a concentrical double cylindrical construction and composed of a cylindricer part 23 admitting passage of a beam, a comical cylinder part 24 situated on its outside, flanges 26, 27 mating with each other, and a ring-shaped coupling part 25 where a carbon plate 13 is installed as a beam absorbent at the foremost of each cylinder part. Using spacer 29 and bolt 30, the flanges of the inlet canal member are installed between a terminal flange 8 of a low energy side accelerator tube 2 and an expansion joint 11 with a stripper canal 9 intruding into it. A high pressure insulative gas makes convection and circulation inside of this double cylindrical construction of the inlet canal member so that heat emitted by the carbon plate is released, and thereby the temp. of the canal member is suppressed low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tandem accelerator which has an inlet canal member having a high cooling efficiency and which is downsized and whose charge conversion efficiency is improved.

[0002]

2. Description of the Related Art FIG. 2 is a schematic diagram of a tandem accelerator.
The accelerator body is housed inside a pressure tank 1 filled with high-pressure insulating gas. The charge conversion unit 3 is coupled to the low energy side acceleration tube 2 into which the negative ion beam is introduced. The converter is located in the high-voltage terminal unit 4, and is configured in such a manner that each set of components is housed in a housing member having expansion joints at both ends. It is installed between the high energy side acceleration tubes 5 that accelerate the ion beam.

FIG. 3 is a sectional view of a portion of the charge conversion section 3 where the negative ion beam is introduced. The low energy side accelerating tube 2 is configured by stacking an accelerating tube electrode 6 and an accelerating tube insulator 7 in multiple stages, and a stripper housing 1 in which a stripper canal 9 is accommodated in a terminal flange 8 of the accelerating tube.
0 are connected via expansion joint 11. An inlet canal member 12 is provided on the negative ion beam incident side of the stripper canal 9, and a carbon plate 13 as a beam absorber is attached to the tip of the inlet canal member 12. The inner diameter of the beam opening 14 of the inlet canal member 12 is the same as the inner diameter of the stripper canal 9, and the right end portion of the canal member has a step portion 15 into which the stripper canal is fitted and which supports the canal, A plurality of circulation openings 16 for stripper gas to be introduced into the stripper canal are formed near this step.

A part of the negative ion beam incident on the entrance canal member 12 does not effectively enter the beam aperture diameter, but collides with the carbon plate 13, and the beam energy is converted into thermal energy. Therefore, the entrance canal member 12
Is made of copper having a high thermal conductivity in order to cool its heat generation, and has a large heat transfer cross-sectional area.
Is formed, and the flange portion is mounted between the stripper housing 10 and the flange of the expansion joint 11.

[0005]

As shown in FIG. 4, the negative ion beam introduced into the low energy side accelerating tube 2 is squeezed by the lens action of the accelerating tube and the entrance canal member 12 is squeezed.
And enters the stripper canal portion of the stripper canal 9. The solid angle of incidence θ of the beam on the canal portion indicates the magnitude of the acceptance of the canal portion. The closer the canal portion is to the accelerating tube 2, the greater the incident angle θ and therefore the acceptance can be increased. The beam incident amount can be increased.

Therefore, if the inlet canal member 12 is disposed closer to the end of the low energy side accelerating tube 2, the acceptance of the stripper canal portion related to the introduction of the negative ion beam from the accelerating tube is increased, and the tandem accelerator. The overall length of the main body can be shortened. In this respect, it is conceivable to directly attach the attachment flange 17 of the inlet canal member 12 to the terminal flange 8 of the low energy side acceleration pipe 2. However, the inlet canal member 12 is radiated and cooled by direct contact of the heat radiation fins 18 with the high-pressure insulating gas in the pressure tank. At this time, the mounting flange 17 is also in a high temperature state, and the heat is transferred to the terminal flange 8. Therefore, it adversely affects the end flange 8 of the accelerating tube 2 and the accelerating tube electrode 6, which are manufactured by the adhesive structure, and the joint between the accelerating tube electrode and the accelerating tube insulator 7.

Further, the inlet canal member 12 is entirely made of solid copper in order to secure heat conduction, and its weight reaches about 15 kg, which is a cause of hindering the weight reduction of the entire charge conversion portion.

According to the present invention, the inlet canal member has a structure that is lightweight and has a high cooling efficiency, and the tandem accelerator is downsized.
The purpose is to improve the charge conversion efficiency.

[0009]

The tandem accelerator of the present invention is provided with an inlet canal member having a beam absorber at the tip, which is provided on the negative ion beam entrance side of a stripper canal for charge conversion, and has a high-pressure insulating gas inside. It is characterized in that it is constituted by a concentric double cylinder that circulates and circulates.

[0010]

[Operation] Since the high pressure insulating gas is convected and circulates inside the concentric double cylinder in the inlet canal member, the entire canal member including the beam absorber mounting portion is cooled,
Since its temperature is kept low, it enables direct attachment of the inlet canal member to the low energy side acceleration tube.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional configuration diagram of the negative ion beam entrance portion of the charge conversion portion, and the same reference numerals as those in FIGS. 2 to 4 denote the same portions. The inlet canal member 22 is coupled to the terminal flange 8 of the low energy side acceleration tube 2. The canal member is formed to have a concentric double cylindrical body as a whole, and includes a cylindrical portion 23 through which the beam passes, a conical cylindrical portion 24 outside the cylindrical portion, and tips of these cylindrical portions. An annular joint portion 25, which is a joint portion, to which a carbon plate as a beam absorber is attached, and flange portions 26, 27, which are flange portions of the respective cylinder portions and are opposed to each other with a space serving as a passage for the high-pressure insulating gas. Consists of.

The stripper canal 9 is a canal support column 2.
8 is supported in the stripper housing 10, and the canal is arranged so that its tip portion enters the inside of the expansion joint 11 connected to the stripper housing. The inlet canal member 22 is attached between the end flange 8 of the low energy side acceleration tube 2 and the expansion joint 11 by means of the flange portions 26 and 27 using a spacer 29 and a bolt 30. In this attachment, first, the flange portion 26 of the inlet canal member 22 is fixed to the terminal flange 8 of the low energy side accelerating pipe 2 with the temporary fixing bolt 31, and the inlet canal member is attached to the low energy side accelerating pipe. Then, the stripper canal 9 is attached to the canal housing 10 by the support column, and the assembly having the expansion joints 11 attached to both ends of the housing is connected to the inlet canal member 22 and the high energy side acceleration tube. That is, when the low energy side acceleration tube 2 and the inlet canal member 22 of the same assembly are attached, the temporary fixing bolt 31 is removed, and the flange portion 2 of the inlet canal member is removed.
A spacer 29 is sandwiched between 6 and 27 and fixed by a bolt 30. The stripper gas introduced into the stripper canal 9 and flowing toward the inlet canal member 22 circulates through the gap 32 between the stripper canal and the inlet canal member.

By attaching the entrance canal member 22 to the low energy side acceleration tube 2, the beam introduction part of the entrance canal member is located immediately after the final stage acceleration tube electrode of the low energy side acceleration tube, and the acceptance of the stripper canal part. Improves the beam transportation efficiency. Due to the arrangement configuration of the stripper canal 9 and the inlet canal member 22, the size of the charge conversion portion located in the high voltage terminal portion is downsized and shortened as a whole.

The energy of the negative ion beam colliding with the carbon plate 13 without entering the cylindrical portion 23 of the inlet canal member 22 is converted into heat energy, and the heat is converted from the cylindrical portion and the conical cylindrical portion 24 into the flange portion. It is transmitted to 26 and 27. Flange portion 26 mounted between the end flange 8 of the low energy side acceleration tube 2 and the expansion joint 11
And 27 facing each other are opened to the high-pressure insulating gas space in the pressure tank, and the high-pressure insulating gas is convected and circulated between the cylindrical portion and the conical cylindrical portion through the facing spacing portion, and the inlet canal member 12 is Dissipate heat. The inlet canal member 22 is entirely formed by convection and circulation of the insulating gas up to the flange portions 26 and 27 including the cylindrical portion 23 and the conical cylindrical portion 24, as well as the annular coupling portion 25 to which the carbon plate 13 is attached. The temperature of the canal member can be kept low because the heat is dissipated and cooled over the entire length.

[0015]

Since the present invention is constructed as described above, since the inlet canal member is formed of a concentric double cylinder body in which high-pressure insulating gas is convected and circulated, the conventional high thermal conductivity, It is much lighter than the one made of large cross section Muku copper, and the temperature of the canal member is cooled by convection and circulation of insulating gas including the mounting part of the beam absorber. Can be lowered, and the emission of outgas is reduced.

Since the temperature of the inlet canal member is kept low, the inlet canal member and therefore the inlet of the stripper canal portion can be arranged close to the low energy side accelerating tube, the acceptance of the canal portion is improved, and the beam The transport efficiency is improved, the size of the charge conversion section can be reduced, and the total length of the tandem accelerator can be shortened.

[Brief description of drawings]

FIG. 1 is a sectional configuration diagram of an embodiment of the present invention.

FIG. 2 is a schematic diagram of a tandem accelerator.

FIG. 3 is a cross-sectional configuration diagram of a negative ion beam introduction portion in a charge conversion unit.

FIG. 4 is an explanatory diagram of beam incidence on a stripper canal portion.

[Explanation of symbols]

 2 Low energy side acceleration tube 9 Stripper canal 10 Stripper housing 11 Expansion joint 13 Beam absorber (carbon plate) 22 Inlet canal member 23 Cylindrical part 24 Conical cylindrical part 25 Annular joint part 26, 27 Flange part 29 Spacer 30 Bolt

Claims (1)

[Claims] 1. An inlet canal member, which is provided on the negative ion beam incident side of a charge conversion stripper canal and has a beam absorber at its tip, has a high-pressure insulating gas convection therein.
A tandem accelerator characterized by being constituted by a concentric double cylinder that circulates.