JP3401279B2 - Ion accelerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion accelerator.
You. [0002] 2. Description of the Related Art FIGS. 3 to 5 show a conventional example.
This shows the ion accelerator, but in these figures
In the ground shield box 41, a high-voltage terminal
Is installed at a predetermined height above ground level.
This is grounded by the four insulating posts 45
It is supported on an insulating support plate 46 provided. High
Distance from voltage terminal 42 to ground level
The intermediate terminal 47 is divided into these
The high voltage terminal 4
2 and the intermediate terminal 47 or the insulating support plate 46
A resistor 48 is connected therebetween. [0003] Also, beside the high voltage terminal 42,
A power supply device 50 is provided, which is a power cable.
The upper end of the shield pipe 57 has a high-voltage terminal.
Null 42 is connected. This conventional power supply device 5
0 is a so-called insulation transformer, and the primary side is a commercial power supply
Is connected, the secondary side extends upward, and its upper end
Covers the corona shield 56. Further, a high voltage power supply is provided beside the power supply device 50.
Power stack (Cockloft-Walton high-voltage power supply)
Source) 51, and an oscillator at the lower end thereof.
52 output terminals are connected via a cable. Ko
Croft-Walton high-voltage power supply 51 is known
It is configured as a stage with diodes, capacitors, etc.
It has a configuration in which the voltage doubler circuit is configured,
As it goes upward, the pressure is increased.
The highest voltage of KV is obtained, and a corona shield 5
4 which is contacted with a high voltage
Terminal 42. A known structure is provided in the high voltage terminal 42.
Source 43, mass separation magnet 44, plasma generation
Power supply 33, drawer power supply 34, gas box 35, etc.
Is provided on one side wall of the high-voltage terminal 42.
Is connected to an acceleration tube 60, and is connected to this.
Focusing Q lens 61, XY scanning unit 62 and
An entry chamber 63 is provided. One end of the acceleration tube 60
Is the same level as the ground shield box 41
You. Further, the exhaust pipe 49 is provided on the other side wall of the high voltage terminal 42.
Between the ground shield box 41 and
Section is connected to the vacuum pump 12. FIG. 6 shows the overall structure of another conventional ion accelerator.
FIG. 3 shows a plan view, in which a high-voltage terminal
1 is disposed in a shield box 2. Above
As in the previous example, the ion source 3 was
Source electrode 4, Plasma generating material gas storage box 6, Plas
Built-in power supply 5
Is slightly different from the above conventional example), and is connected to the ion source 3.
Then, a mass separation magnet 44 is provided as in the conventional case,
It is connected via a conduit 8 to an acceleration tube 60. This
Is connected to the shield box 2. According to this conventional example, the first ion source 3
Vacuum pump 7 is connected, and a second
A vacuum pump 9 is connected. And shield box
A third vacuum pump 12 is provided outside the
And a T-shaped exhaust duct 10 through an exhaust pipe 11.
It is connected to the. This is connected to the first vacuum pump 7
And a second vacuum pump 9 connected to a conduit 8
To assist. Further, the fourth vacuum pump 40 is
Attached to the focusing Q lens unit 61 to exhaust air
Have been killed. Further, according to this conventional example, the power supply device
Of the insulation transformer 14 and the high voltage generator 16
Section 14a and the high voltage generating section 16a
The shield box 2 and the high-voltage tag
And the high voltage generator
To connect the high voltage of the device 16 to the high voltage terminal 1
And bushings 13, 15 made of insulating material
Is connected between the shield box 2 and the high-voltage terminal 1.
Has been continued. The details of the high voltage generator 16 are shown in FIG.
However, the insulating container 16b of the high voltage generator 16a is sealed.
Is fixed to the box 2 and the insulating oil M
Is filled, so that the diode D and the capacitor
The highest voltage section of the voltage doubler circuit section 16A composed of
Connected to the high voltage terminal 1 via the body 16B
You. In FIG. 7, the input terminal of the voltage doubler circuit section 16A is shown.
The output terminals of the oscillator 52 are connected to a and b. The transformer section 14a of the insulating transformer 14 is made of gold.
Metal container 14b, which is also a shield box 2
Fixed on the side wall of the
M, and the primary coil C
₁ , Iron core F, secondary coil C _Two The transformer section consisting of
Has been immersed. Secondary coil C_Two A terminal e derived from
f extends upward, from which the high voltage terminal 1
Ion source 3, mass separation magnet 44, extraction electrode 4
To supply power. The high voltage generator 16 is described above.
This is fixed to the shield box 2
Insulation between field box 2 and high voltage terminal 1
A bushing 15 consisting of
The highest voltage of the high voltage generator 16 is connected to the resistor 16B
But it covers it. Also in the bushing 15
Has metal rings 21 attached at predetermined intervals,
These are connected by a resistor 22. The secondary coil C of the insulation transformer 14_Two Side
It extends to the high voltage terminal 1 side and surrounds it
A bushing 13 made of an insulating material is
It is installed between the high voltage terminal 1 and this
A metal ring 24 is provided on the outer periphery similarly to the high voltage generator 16.
It is fixed at a predetermined interval, and during this time, it is connected by the resistor 25.
Has been continued. Similarly, the exhaust pipe 11 and the acceleration pipe 60 are
The outer periphery is covered with bushings 26 and 29 made of insulating material.
Metal rings 27 and 30 are similarly formed on the outer periphery
It is fixed at a predetermined interval, and the resistor 2
8 and 31 are connected. m is formed in terminal 1
Metal ring fixed around the opening to prevent discharge.
You. The ion accelerator according to the conventional example is described above.
The operation will now be described. The first and the third vacuum pumps 7 and 9
The conductors connected to the ion source 3 and the mass separation magnet 44, respectively.
The tube 8 is reduced to a predetermined pressure. Outside shield box 2
The exhaust pipe 1 is moved by the second vacuum pump 12
1st and 2nd vacuum pumps via 1 and exhaust duct 10
The exhaust pipe 11 and the mass separation magnet 44
Up to a predetermined degree of pressure reduction in the conduit 8 connecting the
Exhaust to lower. In the above-described state, a predetermined
The ions accelerated by the voltage are mass-
And only certain ions are separated by the conduit 8 and the acceleration tube 60.
To the ion implanter 63 via the. The output terminal of the isolation transformer 14 is
Connected to the terminal block 18 through the
Then, electric power is supplied to the mass separation magnet 44 and the ion source 3. The conventional ion accelerator is constructed as described above.
However, in the above conventional example, a metal ring or
The metal hoop is schematically illustrated. Figure 8 shows the details of this.
Is shown. This structure is similar to that of the high voltage generator 16.
Is the same, so the isolation transformer,
Only the feeding device 14 is illustrated. That is, in the power supply device 14,
Thing 13 is attached to casing 14a of the insulation transformer.
It is fixed, but in this internal structure
The secondary windings e and f of the insulated transformer are covered with a metal pipe 73.
Paper with insulating oil impregnated in close contact with it.
The outer cylinder 72 is covered with FRP.
It is covered with an insulating material 74. The metal hoop 24 is located on the outer metal hoop 24.
a, inner metal hoop 24b, connecting these radially
Annular thin plate member 24c.
A bolt insertion hole is formed in the annular thin plate member 24c of the loop 24.
And between the metal hoops 24, FRP
A bolt 81 is inserted with a cylindrical collar 80 made of an edge material interposed.
And tighten the bolts 82 at the upper and lower ends.
By attaching, the metal hoop 24 is integrated. This
The top part of the metal hoop integrated like
By welding to the L-shaped mounting band 83,
It is integrated with the thing 13 and also has an L-shaped cross section at the lower end.
The annular part of the fastening band 84 is welded.
More integrated. The inner metal hoop 24b
An air gap S is provided between the device and the thing 13. Note that FIG.
In this case, the mounting position of the resistor 25 is slightly different from that of the conventional example.
However, the same operation is performed. The metal hoops 24 are arranged in six steps in the example of FIG.
This allows the high voltage terminal 1 and the shield
Of the space between the inner wall of the box 2
However, the output of the insulating transformer through which the bushing 13 is inserted
The force lines e and f, that is, the metal pipe 73 through which these
The same potential as high voltage terminal 1, that is,
Ground level, the ground level
400KV potential difference between the inner wall of the box and
The axial direction of the bushing 13
Potential and radial direction, that is, metal tube 73, insulating material 72 and
The metal hoop inside the metal hoop 24 across the bushing 71
There is a large potential difference between the
Since it changes at each hoop position in the axial direction, each metal hoop 2
4 between the hoop 24b inside the bushing 13 and the bushing 13
The potential vector at is different in the axial direction, which is
Due to the presence of an uneven electric field on the surface of the bushing 13.
Situation where the electric charge is easy to charge and therefore easy to discharge
It is in. [0021] SUMMARY OF THE INVENTION The present invention relates to the above-mentioned problems.
The potential of the surface of the bushing is determined and
Probability of constantly forming a stable electric field and thus triggering a discharge
To provide an ion accelerator capable of reducing
aimed to. [0022] [Means for solving the problems]
Both with built-in ion source and mass separation magnet
At a predetermined height from the ground, and
A predetermined high voltage is applied to the casing to
Supply power to the ion source, mass separation magnet, etc.
And a casing for electromagnetically shielding the casing.
A cold box, and one side of the casing,
Between one side and the inner wall of the shield box facing
In an ion accelerator with an acceleration tube attached to
And one side of the shield body facing the side.
Between the inner wall of the box or the casing and the floor
The column is attached between the
Multiple resistors in series along and around the axis of the body
From the casing.The seal
To the inner wall of the box or to the floorHelix
And wound at one end of the strip of the plurality of resistors.
The resistance is electrically connected to the casing, and the resistance at the other end isPrevious
On the inner wall of the shield box or on the floorElectrical
By an ion accelerator characterized by being connected to
Achieved. [0023] [Function] A bushing, that is, a columnar body made of an insulating material.
To connect multiple resistors in series along its axis
From the ground level to the high potential of the casing
The casing and casing are wound along this axis
Inside of the boxOr with the floorAt equal intervals
Divided, so that the metal hoop
The potential difference between them is almost zero, so that each position in the axial direction
The potential difference at the casing and the inner wall of the shield boxOr
With the floorBetween the equal potentials, and
Discharge without charging the surface of the battery.
The rate can be greatly reduced. [0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ion accelerator according to an embodiment of the present invention.
Will be described with reference to the drawings. The above conventional example
The same reference numerals are used for the parts corresponding to
Detailed description is omitted. That is, in the present embodiment, two of the insulating transformers are used.
On the outer peripheral surface of the metal pipe 73 into which the secondary output wire is inserted.
The paper cylinder 92 impregnated with insulating oil is also covered in
Although it is overturned, as shown in FIG. 2 around this,
A metal ball 91 and a resistor 90 having the same resistance value are alternately and directly connected.
The strip 100 connected to the row is connected to the high-voltage terminal 1
Spirally wound around the inner wall of the box 2
One end of the uppermost resistor 90 is connected to the high voltage terminal 1.
One end of the lowermost resistor 90 is connected to a shield box.
2 is connected to the inner wall. That is, the ground level
You. Insulation oil is further applied to the outer peripheral surface of such a strip 100.
The outer surface of the impregnated paper cylinder 93 is covered with FR.
An insulating material 94 made of P is covered. So as a whole
All the bushings 95 are formed. As clearly shown in FIG. 2, the resistor 90 and the metal
The ball 91 is connected alternately to form the strip 100.
But for one turn of this, that is, one turn, a metal ball
Distance L between 91₁ That is, the winding pitch is between the metal hoops
Distance L_Two Is equivalent to A resistor connected between metal hoops
Between the resistance value of the anti-25 and the metal ball 91 connected for one turn
The total resistance value of the resistor 90 (consisting of 6 pieces) is
It is equal to the resistance value of the resistor 25 between them. The embodiment of the present invention is configured as described above.
The operation will now be described. High voltage
The high voltage of 400 KV generated in the raw part
Is applied to the terminal 1 but is connected to it.
This potential is also applied to the output terminals e and f of the insulating transformer 14.
available. Accordingly, one end of the uppermost resistor 90 in FIG.
This potential is applied to the resistor 90 and the metal ball 9 sequentially.
1, a current flows to the resistor 90 and the ground level side
The potential drops evenly every turn. So this absolute
The outer surface of the bushing made of edging material is
In this case, the potential is lowered. In this embodiment,
Since it is the same as the drop between metal hoops, it is uniform in the axial direction.
A uniform electric field is obtained, so that the charge
Drastically reduce the probability of charging
be able to. The embodiments of the present invention have been described above.
However, of course, the present invention is not limited to this.
Various modifications are possible based on the technical concept of the invention. For example, in the above embodiment, the power supply
I explained about metal hoops, but of course it ’s not limited to this.
For example, instead of this, the output line of the high voltage generator is wound
The strip shown in FIG.
100 from the high voltage terminal 2
It may be wound around the inner wall of the box 1. Alternatively, the high voltage terminal 2 is insulated on the floor
It is supported by columns, but inside this
2 may be wound. [0031] As described above, the ion acceleration of the present invention is
According to the device, the high voltage terminal and the opposing system
Cold box inner wall or high voltage terminal and floor
Bushing made of insulating material provided between
In other words, the electric charge is charged on the surface of the columnar body to generate a discharge.
The probability that the

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view of a main part of an ion accelerator according to an embodiment of the present invention. FIG. 2 is an enlarged cutaway perspective view of a further important part in FIG. FIG. 3 is a partially broken front view of a conventional ion accelerator. FIG. 4 is a sectional view taken along the line [4]-[4] in FIG. FIG. 5 is a partially broken side view of the device. FIG. 6 is a partially broken plan view of another conventional ion accelerator. FIG. 7 is an enlarged sectional view of the main part. FIG. 8 is a partially broken plan view showing a structure for attaching a metal hoop to a bushing of another conventional example. [Description of Signs] 90 Resistance 92 Paper cylinder 100 Strips

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05H 5/02 G21K 5/04

Claims (1)

(57) Claims 1. A casing containing at least an ion source and a mass separation magnet is disposed at a predetermined height from the ground, and a predetermined high voltage is applied to the casing by a high-voltage power supply device. Is applied to supply power to the ion source, the mass separation magnet, and the like by a power supply device, and a shield box that electromagnetically shields the casing is provided. In an ion accelerator in which an acceleration tube is attached between an inner wall surface of the shield box and one side surface of the casing, between the inner wall surface of the shield box facing the side surface, or the casing and the floor surface A column formed by connecting a plurality of resistors in series along and around the axis of the column inside the column made of an insulating material, From pacing to the inner wall of said shield box, and
Is wound spirally on the floor surface, of the plurality of resistors, one end of the strip is electrically connected to the casing, and the other end is an inner wall surface of the shield box.
Or an ion accelerator electrically connected to the floor .