JPH01157044A - Static magnetic field applied type electron gun - Google Patents
Static magnetic field applied type electron gunInfo
- Publication number
- JPH01157044A JPH01157044A JP31325987A JP31325987A JPH01157044A JP H01157044 A JPH01157044 A JP H01157044A JP 31325987 A JP31325987 A JP 31325987A JP 31325987 A JP31325987 A JP 31325987A JP H01157044 A JPH01157044 A JP H01157044A
- Authority
- JP
- Japan
- Prior art keywords
- anode
- ring
- magnetic field
- lens
- permanent magnet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000003068 static effect Effects 0.000 title claims 2
- 239000000696 magnetic material Substances 0.000 claims description 7
- 238000007142 ring opening reaction Methods 0.000 claims description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract description 6
- 239000012212 insulator Substances 0.000 abstract description 6
- 229910052742 iron Inorganic materials 0.000 abstract description 3
- 239000000126 substance Substances 0.000 abstract 6
- 230000002265 prevention Effects 0.000 abstract 1
- 230000004075 alteration Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 230000004907 flux Effects 0.000 description 4
- 230000003287 optical effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000010894 electron beam technology Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
Landscapes
- Electron Sources, Ion Sources (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、永久磁石を用いた熱電子放射型電子銃に関す
る。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermionic emission type electron gun using a permanent magnet.
一般に、電子銃は、電界放射型と熱電子放射型とがあり
、熱電子放射型電子銃はフィラメントを加熱して熱電子
を放射し、バイアス電極により逆バイアスをかけて電子
ビーム電流量を制御している。フィラメントとバイアス
電極の間には電界が形成され、フィラメントからでてく
る電子ビームのクロスオーバーを形成し、これが光源と
みなされている。この種静電レンズを使用する場合、そ
の特性として、収差係数が大きいという問題点を有し°
ζいる。そのため静電レンズに代えて磁界レンズを用い
、収差係数の改善が図られてきた。−般に磁界レンズを
用いると、シャープな磁界を得ることができるという効
果がある。In general, there are two types of electron guns: field emission type and thermionic emission type.Thermionic emission type electron guns heat a filament to emit thermionic electrons, and control the amount of electron beam current by applying a reverse bias using a bias electrode. are doing. An electric field is created between the filament and the bias electrode, creating a crossover of the electron beam coming from the filament, which is considered a light source. When using this type of electrostatic lens, its characteristic is that it has a large aberration coefficient.
There is ζ. Therefore, efforts have been made to improve the aberration coefficient by using a magnetic lens instead of an electrostatic lens. -Using a magnetic field lens generally has the effect of being able to obtain a sharp magnetic field.
また、光源の特性を示すものの一つとして輝度があるが
、フィラメント材料により決まる輝度の理想値が、使用
するレンズ系により実際は悪化する。即ち、収差係数が
大きいとフィラメント材料により決まる輝度の理想値を
悪化させる。Furthermore, one of the characteristics of a light source is brightness, and the ideal value of brightness determined by the filament material actually deteriorates depending on the lens system used. That is, when the aberration coefficient is large, the ideal value of brightness determined by the filament material deteriorates.
そのため、磁界重畳型電子銃は、従来静電レンズのみか
ら形成されていた電子銃近傍のレンズ作用に対し、収差
係数の小さい磁界レンズを持ち込み、光源近傍での収差
係数を小さくして、電子銃の特性を、プローブ径の大き
な、即ち光源での見込み角の大きな領域で改善しようと
するもので第３図に示すような様々な型が考えられてき
た。まず、第３図（ａ）に示すものは、コイル１１、ヨ
ーク１２から形成されるレンズ部が、真空チャンバー２
外の低圧部に設けられているものであり、同図（ｂ）に
示すものは、コイル１１、ヨーク兼用アノード１３から
形成されるレンズ部が、真空チャンバー２内の高圧部に
、碍子ｌ゛により浮がされた状態で設けられているもの
が知られている。Therefore, the magnetic field superimposition type electron gun incorporates a magnetic field lens with a small aberration coefficient to reduce the aberration coefficient near the light source, in contrast to the lens action near the electron gun, which was conventionally formed only from an electrostatic lens. Various types as shown in FIG. 3 have been devised in an attempt to improve the characteristics of the probe in a region where the probe diameter is large, that is, the angle of view at the light source is large. First, in the one shown in FIG. 3(a), the lens portion formed by the coil 11 and the yoke 12 is
The lens part formed by the coil 11 and the anode 13 which also serves as a yoke is installed in the high pressure part inside the vacuum chamber 2, and the one shown in FIG. It is known that the device is installed in a floating state.
しかしながら、第３図（ａ）に示す磁界重畳型電子銃に
おけるレンズ電源の製作は容易であるが、１００ＫＶと
いう高電圧のため、電子銃のチャンバー径りを、放電防
止のため充分に大きくとる必要があり、どうしても距離
を持った所から磁界をかけるため、磁界がブロードであ
るという問題点を有している。そのため、第３図（ｂ）
に示すように、高電圧側に電源を有する磁界レンズを光
源の近くに設ける方法が採用されている。しかじながら
、この方法はフィラメント近傍にレンズを有しているた
め、磁界は有効にかかるが、真空、高圧部に設けるため
、レンズ電源供給のために高圧タンク（図示せず）のパ
ワー伝送トランスを容量の大きなものにする必要があり
、また高圧タンク内回路に整流器、スタビライザー等の
レンズ電源の追加や、高圧ケーブルの芯線の数が増し、
レンズパワーの入力のための端末の処理が複雑なものと
なる等の製作上の問題点を有している。However, although it is easy to manufacture the lens power supply for the magnetic field superimposition type electron gun shown in Figure 3(a), due to the high voltage of 100 KV, the diameter of the chamber of the electron gun must be sufficiently large to prevent discharge. However, since the magnetic field is applied from a distance, the problem is that the magnetic field is broad. Therefore, Fig. 3(b)
As shown in Figure 2, a method has been adopted in which a magnetic field lens having a power source on the high voltage side is provided near the light source. However, since this method has a lens near the filament, the magnetic field is effectively applied, but since it is installed in a vacuum and high-pressure area, a power transmission transformer in a high-pressure tank (not shown) is required to supply power to the lens. In addition, it is necessary to increase the capacity of the high-voltage tank, add a lens power supply such as a rectifier and stabilizer to the circuit inside the high-voltage tank, and increase the number of core wires in the high-voltage cable.
There are manufacturing problems such as complicated terminal processing for inputting lens power.
従って、本発明は磁界レンズと同様、磁界重畳を有効に
行い、かつ光源の近傍で強い磁界を集中でき、上記の問
題点を解決する電子銃を提供することを目的とする。Accordingly, an object of the present invention is to provide an electron gun that can effectively superimpose magnetic fields and concentrate a strong magnetic field near a light source, as well as a magnetic field lens, and that solves the above-mentioned problems.
そのため、本発明は、熱電子放出フィラメントと、該フ
ィラメントを円筒形状のバイアス電極により囲み、アノ
ードに対向して配置した熱電子放射型電子銃であうで、
該バイアス電極のアノード側端部に、リング状の永久磁
石をリング状磁性体に同心状に組み込み、かつリング開
口部近傍には磁性体を配置したレンズ部を嵌合させて取
り付け、さらに該リング開口部のアノード側側面を平滑
に仕上げたことを特徴とするものである。Therefore, the present invention provides a thermionic emission type electron gun including a thermionic emission filament, the filament surrounded by a cylindrical bias electrode, and arranged opposite to an anode.
A ring-shaped permanent magnet is concentrically incorporated into a ring-shaped magnetic body at the anode side end of the bias electrode, and a lens part with a magnetic body arranged near the ring opening is fitted and attached, and the ring It is characterized by having a smooth finish on the side surface of the opening on the anode side.
レンズ部を、電磁石による磁界レンズに代えて永久磁石
による磁界レンズとすることにより、電磁石の場合の電
源を設ける必要がない等の上記問題点を解消しうる。ま
たアノードへの対向面は、高電圧状態にあり、永久磁石
のごとき焼結体の場合、表面が粗いために放電しやすい
。本発明においてはアノードへの対向面に、鉄等の表面
加工のし易い磁性体を配置することにより放電等の問題
を解決したものである。By replacing the magnetic field lens with an electromagnet with a magnetic field lens with a permanent magnet in the lens portion, the above-mentioned problems such as not needing to provide a power source in the case of an electromagnet can be solved. Further, the surface facing the anode is in a high voltage state, and in the case of a sintered body such as a permanent magnet, the surface is rough, so it is easy to discharge. In the present invention, problems such as electrical discharge are solved by arranging a magnetic material such as iron that is easily surface-processed on the surface facing the anode.
以下、図面を用いて、実施例を説明する。 Examples will be described below with reference to the drawings.
第１図は、本発明の電子銃部を示す断面図、第２図は、
本発明の電子銃部の光軸上での各位置での磁束強度を示
す図である。FIG. 1 is a sectional view showing the electron gun section of the present invention, and FIG.
FIG. 3 is a diagram showing the magnetic flux intensity at each position on the optical axis of the electron gun section of the present invention.
図中、１は碍子、２はチャンバー、３はアノード、４は
排気孔、５は開口部、６はフィラメント、７はバイアス
電極、８は磁性体、９は永久磁石、１０は開口部を示す
。In the figure, 1 is an insulator, 2 is a chamber, 3 is an anode, 4 is an exhaust hole, 5 is an opening, 6 is a filament, 7 is a bias electrode, 8 is a magnetic material, 9 is a permanent magnet, and 10 is an opening. .
排気孔４で排気された円筒状の真空チャンバー２中に、
該チャンバー上面よりフィラメント電源に接続されたフ
ィラメント６、およびバイアス電源に接続された導線を
導入し、碍子１により高圧部とは１色緑しておく。そし
てフィラメント６、およびバイアス電源に接続された導
線端部を囲むように、円筒形状のバイアス電極７を碍子
１に取り付け、バイアス電源に接続された導線端部を該
バイアス電極７に接続する。また真空チャンバ−２底面
に開口部５を存するアノード３を、上記フィラメント６
に対向させて配置して高圧部を形成する。In a cylindrical vacuum chamber 2 that is evacuated through an exhaust hole 4,
A filament 6 connected to a filament power source and a conductive wire connected to a bias power source are introduced from the upper surface of the chamber, and the insulator 1 is used to make the high voltage part one color green. A cylindrical bias electrode 7 is attached to the insulator 1 so as to surround the filament 6 and the end of the conducting wire connected to the bias power source, and the end of the conducting wire connected to the bias power source is connected to the bias electrode 7. Further, the anode 3 having an opening 5 on the bottom surface of the vacuum chamber 2 is connected to the filament 6.
A high-pressure part is formed by arranging the parts facing each other.
碍子１に取り付けた上記バイアス電極７の他端部内側に
は、リング状永久磁石９を、中心部に開口部ｌＯを有す
るリング状磁性体８に同心状に組み込んだものを嵌合さ
せて取り付ける。第１図に示すように、リング状磁石９
はアノード３側に配置するように磁性体８に組み込み、
開口部ＩＯ近傍は磁性体８を配置するように紐み込む。Inside the other end of the bias electrode 7 attached to the insulator 1, a ring-shaped permanent magnet 9 is fitted and attached concentrically to a ring-shaped magnetic body 8 having an opening 10 in the center. . As shown in FIG.
is incorporated into the magnetic body 8 so as to be placed on the anode 3 side,
The magnetic material 8 is inserted in the vicinity of the opening IO.
該り；ノブ状磁性体８は、導電性を有する、例えば鉄等
からなり、アノード３へ対向する面は、好ましくはアノ
ード３面に平行に形成すると共に、放電を防止するため
に極めて平滑に仕上げられている。そしてフィラメント
６の先端部は、リング状磁性体８の開口部１０近傍に臨
むように配置され、フィラメント６の先端部に強い磁界
を集中するようにする。The knob-shaped magnetic body 8 is made of conductive material such as iron, and the surface facing the anode 3 is preferably formed parallel to the surface of the anode 3 and extremely smooth to prevent discharge. It is finished. The tip of the filament 6 is arranged so as to face the vicinity of the opening 10 of the ring-shaped magnetic body 8, so that a strong magnetic field is concentrated at the tip of the filament 6.
このように形成された電子銃により形成される磁界分布
図を第２図に示す。横軸に磁性体８の開口部１０先端か
らの光軸線上の距離をとり、縦軸は光軸線上の各位置に
おける磁束強度を示す。第２図に示すごとく、磁性体８
の開口部１０先端近傍に磁束が強く集中していることを
示している。FIG. 2 shows a magnetic field distribution diagram formed by the electron gun formed in this manner. The horizontal axis represents the distance on the optical axis from the tip of the opening 10 of the magnetic body 8, and the vertical axis represents the magnetic flux intensity at each position on the optical axis. As shown in Figure 2, the magnetic material 8
This shows that the magnetic flux is strongly concentrated near the tip of the opening 10.
尚、バイアス電極７先端部を湾曲させて延設し、リング
状永久磁石９部を支えるように構成してもよい。Note that the tip of the bias electrode 7 may be curved and extended to support the ring-shaped permanent magnet 9.
本発明は、従来の電磁石による磁界レンズに代えて、永
久磁石による磁界レンズを採用することにより、電磁石
による磁界レンズの場合の製作上の問題点を解消でき、
しかも、フィラメント近傍にレンズ電源を配置しうると
いう磁界レンズの場合と同様の収差の小さい磁界レンズ
を形成しうるという効果を奏しうるものである。また、
同一ビーム径では、ビームの取り込み角度を大きくしう
るという効果もある。The present invention uses a magnetic field lens using permanent magnets in place of the conventional magnetic field lens using electromagnets, thereby solving manufacturing problems associated with magnetic lenses using electromagnets.
Moreover, it is possible to form a magnetic field lens with small aberrations similar to the case of a magnetic field lens in which a lens power source can be disposed near the filament. Also,
With the same beam diameter, there is also the effect that the beam capture angle can be increased.
第１図は、本発明の電子銃部を示す断面図、第２図は、
本発明の電子銃部の光軸上での各位置での磁束強度を示
す図、第３図は、従来の磁界重畳型電子銃部を示す断面
図である。
図中、■は碍子、２はチャンバー、３はアノード、４は
排気孔、５は開口部、６はフィラメント、７はバイアス
電極、８は磁性体、９は永久磁石、１０は開口部、１１
はコイル、Ｉ２はヨーク、Ｉ３はヨーク兼用のアノード
を示す。
出 願 人 日本電子株式会社
代理人 弁理士 内１）亘彦（外３名）−１０−５０
５（ｍｍ）FIG. 1 is a sectional view showing the electron gun section of the present invention, and FIG.
FIG. 3, which is a diagram showing the magnetic flux intensity at each position on the optical axis of the electron gun section of the present invention, is a sectional view showing a conventional magnetic field superimposition type electron gun section. In the figure, ■ is an insulator, 2 is a chamber, 3 is an anode, 4 is an exhaust hole, 5 is an opening, 6 is a filament, 7 is a bias electrode, 8 is a magnetic material, 9 is a permanent magnet, 10 is an opening, 11
indicates a coil, I2 indicates a yoke, and I3 indicates an anode which also serves as a yoke. Applicant JEOL Co., Ltd. Agent Patent Attorney (1) Nobuhiko (3 others) -10-50
5 (mm)
Claims (1)
のバイアス電極により囲み、アノードに対向して配置し
た熱電子放射型電子銃であって、該バイアス電極のアノ
ード側端部に、リング状の永久磁石をリング状磁性体に
同心状に組み込み、かつリング開口部近傍には磁性体を
配置したレンズ部を嵌合させて取り付け、さらに該リン
グ開口部のアノード側側面を平滑に仕上げたことを特徴
とする静磁界重畳型電子銃Thermionic emission type electron gun includes a thermionic emission filament, the filament is surrounded by a cylindrical bias electrode, and is placed opposite to an anode, and a ring-shaped permanent magnet is attached to the anode side end of the bias electrode. It is characterized in that it is incorporated concentrically into the ring-shaped magnetic material, and that a lens portion on which the magnetic material is arranged is fitted and attached near the ring opening, and that the anode-side side surface of the ring opening is finished smooth. Static magnetic field superimposition type electron gun
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62313259A JPH073771B2 (en) | 1987-12-11 | 1987-12-11 | Static magnetic field superimposing electron gun |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62313259A JPH073771B2 (en) | 1987-12-11 | 1987-12-11 | Static magnetic field superimposing electron gun |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01157044A true JPH01157044A (en) | 1989-06-20 |
| JPH073771B2 JPH073771B2 (en) | 1995-01-18 |
Family
ID=18039050
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62313259A Expired - Lifetime JPH073771B2 (en) | 1987-12-11 | 1987-12-11 | Static magnetic field superimposing electron gun |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH073771B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006324119A (en) * | 2005-05-19 | 2006-11-30 | Hitachi Ltd | Electron gun |
-
1987
- 1987-12-11 JP JP62313259A patent/JPH073771B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006324119A (en) * | 2005-05-19 | 2006-11-30 | Hitachi Ltd | Electron gun |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH073771B2 (en) | 1995-01-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |