JP2002231168A - Wien filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Wien filter of high assemblage precision in which position relation between a yoke and an electrode can be precisely reproduced after dismantling. SOLUTION: This Wien filter 1 is provided with the yoke 2 of a roughly cylindrical form comprising magnetic material. Insulation member inserting holes 2a and 2b are formed in an outer circumferential surface of the yoke 2, and electrode fixing surfaces 2f and 2g and magnetic pole forming members 2c are provided on an inner circumferential surface of it. Insulation members 3 and 4 having screw inserting holes 3a and 4a are inserted into the insulation member inserting holes 2a and 2b. Four insulation plates 6 and 7 comprising cut insulation plate bases have screw inserting holes 6a and 7a, and two of them are used at the time of integral work and final assemblage. The electrodes 8 have positioning side surfaces 8a and 8b having screw holes 8d and 8e, and counter surfaces 8c. The electrodes 8 are fixed by bolts 9 and 10 to the electrode fixing surfaces 2f and 2g through the insulation members 3 and 4. An electromagnetic coil 11 is installed on the magnetic pole forming members 2c and 2c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle beam apparatus used in an electron microscope or the like, in which a charged particle beam is vertically incident while an electric field and a magnetic field are perpendicular to each other to separate charged particles of a predetermined speed traveling straight. About the Wien filter.

[0002]

2. Description of the Related Art Conventionally, a magnetic pole in which an electromagnetic coil is mounted on a magnetic pole forming member integrally formed on the inner peripheral surface of a cylindrical yoke or separately provided as the Wien filter; There is known an electrode provided with an electrode fixed to an electrode support portion separated by a predetermined angle in a direction via an insulator. Such a Wien filter has at least a pair of electrodes and magnetic poles. 5A and 5B are explanatory views of a Wien filter having a pair of electrodes and magnetic poles in the related art. FIG. 5A is a plan view of the Wien filter, and FIG. 5B is a cross-sectional view taken along the line VB-VB in FIG. To facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the right-left direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The directions or sides indicated by Z and -Z are front, rear, right, left, upper, lower, or front, rear, right, left, upper, and lower, respectively. Also, in the figure, those in which “•” is described in “○” mean an arrow pointing from the back of the paper to the front, and “○”
The symbol with “x” in it means an arrow pointing from the front to the back of the paper.

In FIG. 5, a Wien filter 01 is
A substantially cylindrical yoke 02 is provided. A pair of upper and lower screw through-holes 02a, 02a are provided on the outer peripheral surface of the yoke 02 at positions substantially 180 ° apart in the circumferential direction. The inner peripheral surface of the yoke 02 has the screw through hole 02
A pair of magnetic pole forming members 02b, 02b protrude and are provided facing each other at a position substantially 90 ° apart in the circumferential direction from the positions a, 02a. The pair of magnetic pole forming members 02b, 02
b, an electromagnetic coil 03 is attached to each of the magnetic poles 02.
c and 02c are formed respectively. Each screw through hole 0
An insulating member 04 (see FIG. 5B) is fitted into 2a, and a screw through hole 04a is formed in the insulating member 04. A plate-like insulator 0 is provided between the yoke 02 and the electrode 05.
6, and a pair of upper and lower screw through holes 06a, 06a are formed in the insulator 06, respectively. The pair of electrodes 05, 05 are prismatic and have a pair of upper and lower screw holes 05a, 05.
a are respectively formed. The electrode 05 is fixed to the fixing surface of the yoke 02 by a bolt 08 that passes through the screw through hole 04a of the insulating member 04 and the screw through hole 06a of the insulator 06 and is screwed into the screw hole 05a of the electrode 05. The pair of electrodes 05, 05 are arranged at a distance of about 90 ° in the circumferential direction from the magnetic poles 02c, 02c, and an electric field formed between the pair of electrodes 05, 05 and the pair of magnetic poles 02c, 02c,
The magnetic field formed between 02c is substantially orthogonal.

The trajectory of the charged particle beam incident from the entrance 02d of the Wien filter 01 is bent in the direction of the electric field by the electric field formed by the electrodes 05 and 05 and the magnetic field formed by the magnetic poles 02c and 02c. By adjusting the strength of the electric and magnetic fields, only charged particles having a specific energy (charged particles having a specific incident velocity) can travel straight through the filter under certain specific conditions. The charged particles of energy are bent. As a result, charged particles emitted from the emission port 02 e of the Wien filter 01 pass through the slits 07 of the charged particle selection plate 07.
Only charged particles having the desired energy, sorted by a, can be taken out.

The electrodes 05, 0 of the Wien filter 01
The magnetic poles 5 and the magnetic poles 02c, 02c must not only be formed with high precision, but also their positional relationship must be precisely determined and fixed. The following techniques (J01) to (J03) are conventionally known as methods for processing and assembling such a Wien filter 01. (J01) Technique for Assembling Wien Filter Using Assembly Jig FIG. 6 is an explanatory diagram of the conventional Wien filter shown in FIG. 5 and an assembly jig for assembling the Wien filter. In FIG. 6, the assembly jig 09 has a circular flange 09.
and a ring-shaped protruding edge 09b for fitting the yoke 02 of the Vienna filter 01 is provided on the peripheral edge of the flange 09a. The electrode 05 of the Wien filter 01 and the magnetic pole 02
There is provided a prismatic shaft 09c that precisely follows the space shape formed by c. The shaft 09c was inserted into the Wien filter 01 to position and fix the electrode 05 and the magnetic pole 02c.

However, in the technique of (J01),
Wien filter 01 components (yoke 02, electrode 05
And insulator 06 etc.) depending on the degree of processing.
The gap between the electrode 9c and the electrode 05 and the magnetic pole 02c of the Wien filter 01 is too large to ensure the assembly accuracy, or conversely, the gap is too small to allow the shaft 09c to be put into the Wien filter 01. . When the gap between the positioning surface of the assembly jig 09 and the electrode 05 and the magnetic pole 02c is set to be small in order to increase the positioning accuracy of the electrode 05 and the magnetic pole 02c, the assembly jig 09 from the Wien filter 01 is fixed and fixed.
May not be able to be extracted. In addition, electrode 0
5 is fixed to one fixed surface formed on the yoke 02, the positioning accuracy of the electrode 05 on the fixed surface is low,
The assembling accuracy could not be improved.

(J02) Technology for assembling the yoke and the electrode of the Wien filter by providing a fitting portion by processing the yoke and the electrode separately FIG. 7 is an explanatory view of another example of the conventional Wien filter. Components that correspond to the components of the Wien filter described with reference to FIG. 5 are denoted by the same reference numerals, and a description will be given of a changed portion. In this technique, the yoke 02, the electrode 05, and the insulator 06 of the Wien filter 01 are individually processed and assembled, and the yoke 02 is provided with an insulator fitting groove portion 02g, and the electrode 05 is provided with an insulator fitting groove portion 05b. The insulator 06 is fitted into the insulator fitting groove 02g of the yoke 02, and the insulator fitting groove 05b of the electrode 05 is fitted into the end of the insulator 06. However, in this technique (J02), since the yoke 02, the electrode 05, and the insulator 06 are individually processed and assembled, the processing accuracy of the yoke 02, the electrode 05, the insulator 06, and the like must be increased. Further, since the positioning is performed by fitting, the assembling accuracy is not necessarily increased.

(J03) A technique for assembling a Wien filter by partially processing the partially assembled Wien filter with a processing machine, and then disassembling the Wien filter. The technique (J03) will be described using the Wien filter shown in FIG. explain. Conventionally, the yoke 02
The electrode 05 is screwed via an insulator 06 to a Wien filter (hereinafter, referred to as the assembled filter) excluding the electromagnetic coil 03.
The “partial assembly Wien filter” 01 is integrally processed by a wire electric discharge machine or the like. When the partially assembled Wien filter 01 is integrally processed in this way,
Since the electrode 05 and the magnetic pole 02c fixed to the yoke 02 via the insulator 06 can be processed in an assembled state, the mutual positional relationship between the electrode 05 and the magnetic pole 02c is correctly positioned, and the precision is relatively easily increased. There is an advantage that can be processed. However, if the integrally processed partially assembled Wien filter 01 is washed without being disassembled, it is difficult to clean dirt attached to the mating surface of each part. There is a possibility that the evacuation of the arranged vacuum chamber becomes worse or the sample is contaminated. In the case where an insulator such as alumina, which is often used, is used as the insulator 06, it is necessary to replace the insulator 06 used for integral processing because there is a possibility that dirt may not be removed even when disassembled and washed. Also,
If the electromagnetic coil 03 is to be mounted on the magnetic pole forming member 02b without disassembling the partially assembled Wien filter 01, the electrode 05 is in the way and the electromagnetic coil 03 cannot be easily attached or detached. It takes troublesome work to mount. Therefore, it is necessary to disassemble the partially-assembled Wien filter 01 which has been integrally processed and clean it before assembling it into the Wien filter 01.

[0009]

However, when the partially assembled Wien filter 01 that has been integrally processed is disassembled and cleaned, and the Wien filter 01 is reassembled, the electrode 0
The relative positional relationship between the magnetic pole 5 and the magnetic pole 02c may be deviated from the positional relationship obtained by integrally processing, and high assembly accuracy may not be achieved. In view of the circumstances described above, the present invention provides the following content (O01),
(O02) is the subject. (O01) To provide a Wien filter with high assembling accuracy capable of accurately reproducing the positional relationship between the yoke and the electrode before and after disassembly and disassembly of the yoke and the electrode of the Wien filter. (O02) To provide a Wien filter with high assembling accuracy capable of accurately reproducing the positional relationship between the yoke and the magnetic pole forming member before and after disassembly when the yoke and the magnetic pole forming member of the Wien filter are disassembled and assembled. thing.

[0010]

Next, a description will be given of the present invention which has solved the above-mentioned problems. In the description of the present invention, reference numerals in parentheses added after constituent elements of the present invention denote constituent elements of the present invention. Reference numerals of corresponding components of the embodiment described later. The reason why the present invention is described in association with the reference numerals of the components of the embodiments described later is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

(1st invention) In order to solve the aforementioned problem,
The Wien filter of the first invention has the following (A01) to (A0).
(A01) A pair of magnetic pole forming members (2c, 2c) protruding from the cylindrical inner peripheral surface and arranged to face each other to form a magnetic field between them.
And a pair of electrode supporting portions (2e, 2e) for forming an electric field orthogonal to a magnetic field formed between the pair of magnetic pole forming members (2c, 2c).
e, 2e), a cylindrical yoke (2) made of a magnetic material formed with two electrode fixing surfaces (2f, 2g) intersecting with each other, (A02) of each of the electrode support portions (2e, 2e). A pair of electrodes (8, 8) fixed to the two electrode fixing surfaces (2f, 2g) with an insulating plate (6, 7) interposed therebetween.
8), (A03) The magnetic pole forming members (2c, 2c) are excited so that a pair of magnetic poles (2d, 2d) having different polarities are formed on the opposing surfaces of the magnetic pole forming members (2c, 2c). Electromagnetic coils (11, 11).

The “two electrode fixing surfaces (2f, 2g) that intersect each other” means “electrode fixing surfaces (2f, 2g) arranged in two planes that intersect each other”.

(Operation of the First Invention)
In the Wien filter of the present invention, the cylindrical yoke (2) made of a magnetic material has a pair of magnetic pole forming members (2c, 2c) arranged at opposing positions on the cylindrical inner peripheral surface. The pair of magnetic pole forming members (2c, 2c) are electromagnetic coils (11, 11).
Thereby, a pair of magnetic poles (2d, 2d) having different polarities are formed on the opposing surfaces of the magnetic pole forming members (2c, 2c).
A magnetic field is formed between the pair of magnetic poles (2d, 2d). Each of the pair of electrode support portions (2) is set at a distance of about 90 ° in the circumferential direction from the pair of magnetic pole forming members (2c, 2c).
e, 2e) intersecting electrode fixing surfaces (2f, 2g)
, The electrode (8) is fixed across the insulating plates (6, 7). Since the electrodes (8, 8) are fixed by two mutually intersecting electrode fixing surfaces (2f, 2g), reassembly after disassembly is performed as compared with the case where the electrodes (8, 8) are fixed by one electrode fixing surface. And the positioning accuracy in the case of the contact is improved. Therefore, even if the Wien filter (1) is disassembled and reassembled, high assembly accuracy can be realized. For this reason, a partially assembled Wien filter in which the yoke (2) and the electrodes (8, 8) are integrally assembled without the electromagnetic coils (11, 11) is integrally processed using a wire electric discharge machine or the like. Then disassemble the electromagnetic coil (1
1,11) and the electrodes (8,8) are reassembled,
It is possible to fix the magnetic pole forming member (2c, 2c) and the electrode (8, 8) in a state where the positional relationship between them is accurately determined. Further, in the Wien filter of the first invention having the above-described configuration, the magnetic pole forming members (2c, 2c) and the yoke (2) are integrally formed, so that there is no need to perform an assembling operation thereof.

(Second Invention) The Wien filter according to the second invention has the following components (A01 '), (A02), and (A02).
02 ') and (A03). (A01 ') A pair of magnetic pole forming members (13,
13) and a pair of magnetic pole supporting portions (2p, 2p) arranged opposite to the cylindrical inner peripheral surface, and a pair of electrodes (8, 8; 16,) generating an electric field substantially orthogonal to the magnetic field. 1
6), a pair of electrode support portions (2e, 2e; 2k,
2k), and each of the magnetic pole support portions (2p, 2p) has two magnetic pole fixed surfaces (2x, 2p) crossing each other.
y) is formed, and each of the electrode support portions (2e, 2e; 2) is formed.
k, 2k), a cylindrical yoke (2) made of a magnetic material formed with two electrode fixing surfaces (2f, 2g; 2m, 2n) intersecting each other, and (A02) the electrode support portions (2
e; 2k) the two electrode fixing surfaces (2f, 2g; 2
m, 2n) with a pair of electrodes (8, 8; 16, 1) fixed to each other with an insulating plate (6, 7; 17, 17) interposed therebetween.
6), (A02 ') A pair of the magnetic pole forming members (13, 13) fixed to the two magnetic pole fixing surfaces (2x, 2y) of the magnetic pole support portions (2p), and (A03) the magnetic pole formations The electromagnetic coils (11, 13) that excite the pair of magnetic pole forming members (13, 13) such that a pair of magnetic poles (13e, 13e) having different polarities are formed on the opposing surfaces of the members (13, 13).
11).

(Operation of the Second Invention)
In the Wien filter according to the present invention, the pair of magnetic pole supporting portions (2p, 2p) arranged opposite to the cylindrical inner peripheral surface of the cylindrical yoke (2) made of a magnetic material include two magnetic pole fixing surfaces that intersect each other. (2x, 2y), and each of the magnetic pole forming members (13) is formed by the two magnetic pole fixing surfaces (2x, 2y).
Is fixed. Therefore, the electromagnetic coils (11, 11)
Excluding the yoke (2) and the magnetic pole forming member (13, 1).
3) The partially assembled Wien filter in which the electrodes (8, 8; 16, 16) and the like are integrally assembled is integrally processed using a wire electric discharge machine or the like, and then disassembled to obtain a magnetic pole forming member (13, 13), the magnetic coils (11, 11) and the electrodes (8, 8; 16, 16) are reassembled, but the magnetic pole forming member (13, 13) and the electrodes (8, 8; 16, 1)
6) It can be fixed in a state where the positional relationship between them is accurately positioned. That is, the magnetic pole forming member (13) is fixed by the two magnetic pole fixing surfaces (2x, 2y) of the magnetic pole support (2p) and the electrodes (8; 16) are fixed to the electrode support (2p).
e; 2k) two electrode fixing surfaces (2f, 2g: 2m, 2
n), one magnetic pole fixing surface and 1
The positioning accuracy when reassembling after disassembly is improved as compared with the case where the electrodes are fixed by two electrode fixing surfaces.

[0016]

(Embodiment 1) A Wien filter according to Embodiment 1 of the present invention is characterized in that the first or second invention has the following configuration requirement (A04). (A04) The insulating plate (6, 7, 17) constituted by one of a plurality of insulating plates of the same shape formed by cutting one insulating plate substrate (60).

(Operation of the First Embodiment) In the Wien filter of the first embodiment having the above configuration, the insulating plates (6, 7, 17) are made of one insulating plate substrate (60).
, And a plurality of insulating plates (6, 7, 17) having the same shape can be easily manufactured.
Therefore, the cut insulating plate (6, 7, 17)
When the electrodes are replaced and assembled, the shapes of the insulating plates (6, 7, 17) before and after replacement are the same, so that the electrodes (8, 16) are almost the same as before the replacement of the insulating plates (6, 7, 17). It can be positioned at the same position.

[0018]

Next, specific examples (examples) of embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following examples. FIG. 1 is a plan view of a Wien filter according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram of the insulating plate according to the first embodiment. In FIG. 1, the Wien filter 1 is
A substantially cylindrical magnetic material yoke 2 is provided. In the outer peripheral surface of the yoke 2, a pair of upper and lower (a pair of Z-axis) insulating member insertion holes 2a, 2a are formed on side surfaces in the left-right direction (Y-axis direction), respectively. A pair of upper and lower (a pair in the Z-axis) insulating member insertion holes 2b, 2 are located rearward (in the −X direction) from the positions 2a, 2a.
b are formed respectively. On the inner peripheral surface of the yoke 2, a pair of magnetic pole forming members 2c, 2c having a substantially rectangular planar shape protrude and are provided facing each other at front (X side) and rear (−X side) positions. Have been. The pair of magnetic pole forming members 2c have parallel facing surfaces 2d.

A pair of left and right electrode support portions 2e, 2e are formed on the inner peripheral surface of the yoke 2, respectively, and the pair of electrode support portions 2e, 2e are connected to the right and left positioning electrode fixing surfaces 2f, 2f. , These electrode fixing surfaces 2 for left and right positioning
f, 2f, an electrode fixing surface 2g for front-rear positioning at a substantially right angle.
2 g each. A plane including the facing surface 2d of the magnetic pole forming member 2c is formed to intersect with a plane including the left and right positioning electrode fixing surface 2f.
Each insulating member insertion hole 2a and each insulating member insertion hole 2b
An insulating member 3 and an insulating member 4 are respectively inserted into the, and a screw through hole 3a and a screw through hole 4a are formed in the insulating member 3 and the insulating member 4, respectively.

In FIG. 2, the insulating plate 6 is made of one insulating plate base material 6 which has been processed with high precision with a substantially uniform thickness t.
0 is cut into four pieces. In each of the cut insulating plates 6, screw through holes 6a are formed corresponding to the positions of the insulating member insertion holes 2a of the yoke 2.
reference). Similarly, the insulating plate 7 is formed by cutting one insulating plate base material into four sheets, and the insulating plate 7 is formed with a screw through hole 7a. These four insulating plates 6 and 7 are integrated at the time of integral processing (when integrally processed by electric discharge machining or the like in a state where they are partially assembled except for the electromagnetic coil), and at the time of final assembly (when the integrated processing is performed). Used when disassembling and reassembling). Since the insulating plates 6 and 7 have a substantially uniform thickness t, the insulating plates 6 and 7 for integral processing and the insulating plates 6 and 7 for final assembly can be replaced when the Wien filter 1 is assembled. In addition, it is possible to prevent a large difference in assembly accuracy. The length of the insulating plate 6 in the vertical direction (Z-axis direction) is slightly smaller than the length of the yoke 2 in the vertical direction.

The electrode 8 is made of conductive metal and has a left-right positioning side surface 8a, a front-rear positioning side surface 8b, an opposing surface 8c, and the like.
a and a pair of upper and lower screw holes 8d and 8e are formed in the front and rear positioning side surfaces 8b. The vertical length of the electrode 8 is substantially the same as the vertical length of the yoke 2. The electrode 8 includes a bolt 9 that penetrates through the insulating member 3 and the insulating plate 6 and is screwed into a screw hole 8d of the electrode 8, and the insulating member 4 and the insulating plate 7
Is fixed to the electrode fixing surfaces 2f and 2g by bolts 10 that pass through the holes and screw into the screw holes 8e of the electrode 8. The electromagnetic coil 11 includes a pair of magnetic pole forming members 2 c and 2 of the yoke 2.
c, and when the electromagnetic coil 11 is energized, the magnetic poles 2d, 2d are formed by the opposing surfaces 2d, 2d at the tips of the magnetic pole forming members 2c, 2c.

(Operation of the First Embodiment) In the first embodiment having the above-described structure, the insulating plate 6 is obtained by processing one insulating plate base material 60 (see FIG. 2) with a high precision to substantially the same thickness t. The product is cut into four insulating plates 6 of the same shape. The insulating plate 7 is similarly manufactured. Next, a left-right positioning side surface 8a and a front-rear positioning side surface 8b of the electrode 8 are provided on the left-right positioning electrode fixing surface 2f and the front-rear positioning electrode fixing surface 2g of the yoke 2, and the insulating plate 6 and the Positioning the insulating plate 7 in between, the bolts 9 and 10 are screwed into the screw holes 8 d and 8 e of the electrode 8 and tightened. In this way,
The partially assembled Wien filter 1 excluding the electromagnetic coil 11 is prepared.

Then, the partially assembled Wien filter is integrally processed using a wire electric discharge machine or the like. The bolts 9 and 10 of the integrally processed Wien filter 1 are loosened and removed, and the yoke 2, the electrode 8 and the insulating plates 6 and 7 are disassembled, respectively. The disassembled yoke 2 and electrode 8 are cleaned. The magnetic pole forming member 2c of the washed yoke 2
Is mounted with the electromagnetic coil 11. Then, instead of the insulating plates 6 and 7 for integral processing, the insulating plates 6 and 7 for final assembly are used.
Again, in the same manner as described above, the left-right positioning side surface 8a and the front-rear positioning side surface 8b of the electrode 8 are attached to the left-right positioning electrode fixing surface 2f of the yoke 2 and the front-rear positioning electrode fixing 2g. , Insulating plate 6 between them
And the insulating plate 7 are positioned therebetween, and the yoke 2
The electrode 8 is fixed with bolts 9 and 10. Thus, the Wien filter 1 is finally assembled.

In the first embodiment, after the partially assembled Wien filter 1 is integrally processed, the left and right positioning of the electrode 8 is performed on the left and right positioning electrode fixing surface 2f of the yoke 2 and the front and rear positioning electrode fixing surface 2g. The insulating plate 6 and the insulating plate 7
And can be fixed with bolts 9 and 10. Therefore, the Wien filter 1 can be assembled accurately without using an assembly jig, and high assembly accuracy can be obtained without lowering the assembly accuracy even when disassembled and assembled. Further, in the first embodiment, since the insulating plate 6 and the insulating plate 7 are obtained by processing a single insulating plate base material 60 with high precision to a substantially same thickness and cutting the same, the insulating plate 6 for integral processing is formed. , 7 and the insulating plates 6 and 7 for final assembly are not changed so that the final assembly accuracy of the Wien filter 1 does not change much, and the vacuum of the charged particle beam device is deteriorated by contamination of the insulating plates and the like. Or the sample is not contaminated.

(Embodiment 2) FIG. 3 is a sectional view of a Wien filter according to Embodiment 2 of the present invention. In the description of the second embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 3, a pair of magnetic pole support portions 2p and 2 are provided on the inner peripheral surface of the yoke 2 at the front (X side) and rear (−X side) positions.
p protrudes and is provided to face. At the tip of each of the magnetic pole supporting portions 2p, two magnetic pole fixing surfaces 2 which are substantially perpendicular to each other are provided.
x and 2y are formed in a V-shape. A clearance groove 2q extending vertically (Z-axis direction) is formed at the boundary between the two magnetic pole fixed surfaces 2x and 2y. A pair of upper and lower (a pair separated in the Z-axis direction) screw through-holes 2r, 2r are formed from the outer peripheral surface of the yoke 2 toward the bottom of the escape groove 2q.

The magnetic pole forming member 13 is composed of two positioning surfaces 13a and 13b and right and left parallel side surfaces 13c and 13
d, and an opposing surface 13e, and the positioning surfaces 13a, 13b are the two magnetic pole fixing surfaces 2x, 2
It is positioned in contact with y. A pair of upper and lower (a pair separated in the Z-axis direction) screw holes 13f, 13f are formed at the connection between the positioning surfaces 13a, 13b of the magnetic pole forming member 13, respectively. The magnetic pole forming member 13 is fixed in a state where the magnetic pole forming member 13 is pressed against the magnetic pole fixing surfaces 2x and 2y by bolts 14 screwed into the screw through holes 2r of the yoke 2. The electromagnetic coil 11 is mounted on the pair of magnetic pole forming members 13, 13, respectively. The pair of magnetic pole forming members 13, 13
When power is supplied to the electromagnetic coil 11 mounted on the pair, the opposing surfaces 13e of the pair of magnetic pole forming members 13 become magnetic poles 13e.

(Operation of the Second Embodiment) In the second embodiment having the above-described configuration, similarly to the first embodiment, parts other than the electromagnetic coil 11 (the yoke 2, the electrode 8, the magnetic pole forming member 13 and the like) are partially used. An assembled Wien filter 1 is created. The partially assembled Wien filter 1 is integrally processed using a wire electric discharge machine or the like. Next, the bolts 9, 10, and 14 of the partially assembled Wien filter 1 that have been integrally processed are loosened and removed.
The yoke 2, the electrode 8, the insulating plates 6, 7, and the magnetic pole forming member 13 are disassembled, respectively. Next, the disassembled yoke 2,
The electrode 8 and the magnetic pole forming member 13 are cleaned. The magnetic coil 11 is mounted on the cleaned magnetic pole forming member 13, and the positioning surfaces 13a and 13b of the magnetic pole forming member 13 are brought into contact with the two magnetic pole fixing surfaces 2x and 2y of the magnetic pole support portions 2p of the yoke 2 for positioning. Then, the bolt 14 is screwed into the screw hole 13f of the magnetic pole forming member 13 from the screw through hole 2r of the yoke 2 and tightened to fix the magnetic pole forming member 13 to the magnetic pole support 2p.

In the second embodiment, since the magnetic pole forming member 13 is positioned and fixed by the two magnetic pole fixing surfaces 2x and 2y of the yoke 2, reassembly can be performed in substantially the same positional relationship as that at the time of the integral processing. Further, the magnetic pole forming member 1
Since the work of mounting the electromagnetic coil 11 on 3 is easy,
The efficiency of the assembly work of the Wien filter 1 can be increased. The reassembling operation of the electrode 8 can be performed in the same manner as in the first embodiment.

(Embodiment 3) FIG. 4 is a sectional view of a Wien filter according to Embodiment 3 of the present invention. In the description of the third embodiment, components corresponding to the components of the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 4, a pair of electrode support portions 2k, 2 is provided on the inner peripheral surface at the left (−Y side) and right (Y side) positions of the yoke 2.
k are protruded and provided to face each other, and two electrode fixing surfaces 2m,
2n are formed in a V-shape. A pair of upper and lower insulating member insertion holes 21 is formed on the outer peripheral surface of the yoke 2 toward the pair of left and right electrode support portions 2k, 2k. An insulating member 15 is inserted into each of the insulating member insertion holes 21, and a screw through hole 15a is formed in the insulating member 15.

The electrode 16 is a prism having two substantially right-angled positioning surfaces 16a and 16b, front and rear parallel side surfaces 16c and 16d, and an opposing surface 16e.
6a and 16b are positioned in contact with the two electrode fixing surfaces 2m and 2n. Positioning surface 16a, 1 of electrode 16
A pair of upper and lower (a pair separated in the Z-axis direction) screw holes 16f, 16f are formed in the connection portion 6b, respectively. The insulating plate 17 is formed by cutting a single insulating plate base material (not shown), which has been processed with high accuracy at a substantially uniform thickness, into eight sheets. These eight insulating plates 17
Are used at the time of integral processing and at the time of final assembly, respectively.
The electrode 16 penetrates the insulating member 15 and
The positioning surfaces 16a and 16b are fixed to the electrode fixing surfaces 2m and 2n via the insulating plate 17 by bolts 18 screwed into the screw holes 16f.

(Operation of the Third Embodiment) In the third embodiment having the above configuration, similarly to the second embodiment, components (the yoke 2, the electrode 16, the magnetic pole forming member 13 and the like) excluding the electromagnetic coil 11 are provided.
To create the partially assembled Wien filter 1. The partially assembled Wien filter 1 is integrally processed using a wire electric discharge machine or the like. Next, the bolts 14 and 18 of the integrated partially assembled Wien filter 1 are loosened and removed, and the yoke 2, the electrode 16, the insulating plate 17, and the magnetic pole forming member 1 are removed.
3 is disassembled. Next, the disassembled yoke 2, the electrode 16, and the magnetic pole forming member 13 are washed. Then, using the insulating plate 17 for final assembly in place of the insulating plate 17 for integral processing, the positioning surfaces 16a of the electrodes 16 are fixed to the electrode fixing surfaces 2m and 2n of the electrode support portions 2K of the yoke 2 again.
16b are positioned with the insulating plate 17 interposed therebetween, and the bolt 18 is screwed into the screw through hole 15a of the insulating member 15.
Into the screw hole 16f of the electrode 16 from above, and tighten and fix. In the third embodiment, since the electrode 16 is positioned and fixed by the two electrode fixing surfaces 2m and 2n of the pair of electrode support portions 2K of the yoke 2, it is possible to perform reassembly in substantially the same positional relationship as at the time of the integral processing. it can. The magnetic pole 1
The reassembling operation of 3e can be performed in the same manner as in the second embodiment.

(Modifications) Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, but falls within the scope of the present invention described in the appended claims. Thus, various changes can be made. Modified embodiments of the present invention will be exemplified below. (H01) In Examples 1, 2 and 3,
Although the insulating plates 6, 7 and the insulating plate 17 are cut by processing one insulating plate base material, they may be formed from separate insulating plate base materials. That is, since the insulating plates 6 and 7 and the insulating plate 17 are plate-like members having relatively small areas, those having substantially the same thickness can be manufactured relatively easily and accurately. Therefore, even if the insulating plate 6 and the insulating plate 7 are separately manufactured for integral processing and for final assembly,
If a high-precision part is selected and used by measurement, the final assembly accuracy of the Wien filter 1 does not decrease so much. In addition, if the insulating plate for integral processing is made of an inexpensive and easy-to-process material such as iron, brass, or aluminum, and if only the insulating plate for final assembly is made of a material that can be processed with high accuracy, cost will be reduced. Can go down. (H02) In the second embodiment, the pair of bolts 14 are screwed into the pair of upper and lower screw holes 13f of the magnetic pole forming member 13 from the pair of upper and lower screw through holes 2r of the yoke 2; With a configuration in which a force is evenly applied to the 2p magnetic pole fixing surfaces 2x and 2y from the positioning surfaces 13a and 13b of the magnetic pole forming member 13, the number and positions of the fixing members, for example, bolts can be changed. (H03) In Examples 1, 2 and 3,
Although the pair of electrodes 8, 16 and the magnetic poles 2d, 13e are provided, it is also possible to provide a plurality of electrodes and magnetic poles.

[0033]

The Wien filter of the present invention described above has the following effects (E01) and (E02). (E01) Since the electrodes are fixed by the two electrode fixing surfaces provided on the Wien filter yoke, when the Wien filter yoke and the electrode are disassembled and assembled, the positions of the yoke and the electrode before and after disassembly are determined. Relationships can be accurately reproduced. That is, it is possible to provide a Wien filter with high assembling accuracy of the yoke and the electrode. Also,
When the electrode and the magnetic pole forming member of the partially assembled Wien filter in which the components excluding the electromagnetic coil are integrated are integrally processed, the positional relationship between the electrode and the magnetic pole forming member can be obtained with relatively high precision. By disassembling and reassembling, the Wien filter in which the yoke, the electrode, and the magnetic pole forming member are positioned with high precision can be manufactured. If the insulating plate used in the Wien filter is not a large area, it can be processed relatively easily and accurately to the same thickness over the entire surface. In many cases,
The insulating plate used in the Wien filter may have a small area. For this reason, it is possible to manufacture a plurality of insulating plates of the same shape having a uniform thickness with extremely high accuracy. Therefore, it is possible to use another insulating plate having the same shape at the time of integral processing and at the time of disassembly and disassembly and reassembly after cleaning. Even if a (dirty insulating plate) is used, the positional relationship between the electrode and the magnetic pole forming member can be reproduced with high accuracy. (E02) Since the yoke of the Wien filter and the magnetic pole forming member are formed separately and the magnetic pole forming member is fixed by the two magnetic pole fixing surfaces provided on the Wien filter yoke, the yoke of the Wien filter and the magnetic pole forming member are disassembled. Also, when assembling is performed, the positional relationship between the yoke and the magnetic pole forming member can be accurately reproduced before and after disassembly. That is, it is possible to provide a Wien filter with high assembling accuracy of the yoke and the magnetic pole forming member.

[Brief description of the drawings]

FIG. 1 is a first embodiment of a Wien filter of the present invention.
FIG.

FIG. 2 is an explanatory diagram of an insulating plate according to the first embodiment.

FIG. 3 is a second embodiment of the Wien filter of the present invention.
FIG.

FIG. 4 is a diagram illustrating a Wien filter according to a third embodiment of the present invention.
FIG.

FIG. 5 is an explanatory diagram of a conventional Wien filter.
5A is a plan view, and FIG. 5B is a vertical sectional view taken along line VB-VB of FIG. 5A.

6 is an explanatory view of the conventional Wien filter shown in FIG. 5 and an assembly jig for assembling the Wien filter.

FIG. 7 is an explanatory diagram of another example of a conventional Wien filter.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 Wien filter 2 yoke 2 c magnetic pole forming member 2 d 13 e magnetic pole 2 e 2 k electrode support 2
f, 2g; 2m, 2n: electrode fixing surface, 2p: magnetic pole support,
2x, 2y: magnetic pole fixing surface, 6, 7, 17: insulating plate, 8, 16: electrode, 11: electromagnetic coil 13: magnetic pole forming member, 60: insulating plate base material,

Claims (2)

[Claims] 1. A Wien filter comprising the following components (A01) to (A03): (A01) a Wien filter protruding from an inner peripheral surface of a cylindrical shape and arranged so as to oppose a magnetic field between them. A pair of magnetic pole forming members to be formed, and a pair of electrode supporting portions for forming an electric field orthogonal to a magnetic field formed between the pair of magnetic pole forming members, and each of the electrode supporting portions intersects with each other. (A02) a pair of the electrodes fixed to the two electrode fixing surfaces of each of the electrode support portions with an insulating plate interposed therebetween; (A03) An electromagnetic coil that excites the magnetic pole forming members such that a pair of magnetic poles having different polarities are formed on the opposing surfaces of the magnetic pole forming members. 2. The following components (A01 '), (A02),
A Wien filter comprising (A02 ') and (A03); and (A01') a pair of Wien filters which support a pair of magnetic pole forming members for forming a magnetic field and are disposed opposite to the cylindrical inner peripheral surface. A magnetic pole support portion, and a pair of electrode support portions for supporting a pair of electrodes that generate an electric field substantially orthogonal to the magnetic field, wherein each of the magnetic pole support portions is formed with two magnetic pole fixed surfaces that cross each other. A cylindrical yoke made of a magnetic material having two electrode fixing surfaces intersecting with each other on each of the electrode supporting portions; and (A02) an insulating plate sandwiched between the two electrode fixing surfaces of each of the electrode supporting portions. (A02 ') a pair of the magnetic pole forming members fixed to the two magnetic pole fixing surfaces of the respective magnetic pole support portions;
(A03) An electromagnetic coil that excites the magnetic pole forming members such that a pair of magnetic poles having different polarities is formed on the opposing surfaces of the magnetic pole forming members.