JPH0250577B2 - - Google Patents
Info
- Publication number
- JPH0250577B2 JPH0250577B2 JP54057395A JP5739579A JPH0250577B2 JP H0250577 B2 JPH0250577 B2 JP H0250577B2 JP 54057395 A JP54057395 A JP 54057395A JP 5739579 A JP5739579 A JP 5739579A JP H0250577 B2 JPH0250577 B2 JP H0250577B2
- Authority
- JP
- Japan
- Prior art keywords
- cathode
- discharge
- lab
- plasma
- auxiliary
- 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.)
- Expired - Lifetime
Links
- 239000002131 composite material Substances 0.000 claims description 7
- 229910025794 LaB6 Inorganic materials 0.000 claims 1
- 239000007789 gas Substances 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
- H01J1/02—Main electrodes
- H01J1/13—Solid thermionic cathodes
Landscapes
- Solid Thermionic Cathode (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、プラズマ電子ビーム、イオン源等に
使用するプラズマ生成用複合型LaB6陰極に関す
る。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a composite LaB 6 cathode for plasma generation used in plasma electron beams, ion sources, etc.
（従来の技術）
従来のプラズマ生成用陰極は、直熱Ｗ製フイラ
メント、酸化物陰極、初期放電で加熱するTa製
パイプ、Ｗ製棒等の陰極などが使用されている。(Prior Art) Conventional cathodes for plasma generation include cathodes such as a directly heated W filament, an oxide cathode, a Ta pipe heated by initial discharge, and a W rod.
（発明が解決しようとする課題）
プラズマ生成用放電陰極は、(1)構造が簡単であ
ること、(2)放電のスタートが容易であること、(3)
大電流を得ることができること、(4)空気にさらさ
れても安定していること、(5)寿命が長いこと、な
どの条件を充たすことが好ましい。(Problems to be Solved by the Invention) A discharge cathode for plasma generation has (1) a simple structure, (2) easy start of discharge, and (3)
It is preferable to meet the following conditions: (4) be able to obtain a large current, (4) be stable even when exposed to air, and (5) have a long life.
しかし、直熱Ｗ製フイラメントは上記(3)及び(5)
の条件で不利であり、酸化物陰極は(4)の条件を充
たしておらず、外部加熱をしないで初期放電で加
熱するTa製パイプ及びＷ製棒陰極は(3)の条件を
充たすようにすると、(2)及び(5)で不利になる。即
ち、大電流を得るには、陰極の体積を大きくする
か、2800℃以上の高温に保持する必要がある。 However, the directly heated W filament is as described in (3) and (5) above.
The oxide cathode does not satisfy the condition (4), and the Ta pipe and W rod cathode, which are heated by initial discharge without external heating, satisfy the condition (3). Then, you will be at a disadvantage in (2) and (5). That is, in order to obtain a large current, it is necessary to increase the volume of the cathode or to maintain it at a high temperature of 2800° C. or higher.
また、LaB6陰極を用いることを想定すると、
Ｗ製フイラメントで外部加熱すれば1800℃で40／
cm2以上の大電流密度を得ることが可能であり、上
記(2)〜(5)の条件を充たすことになるが、長時間大
電流を得るために必然的に大きな表面積と体積が
必要になり外部加熱のＷ製フイラメントパワーが
極めて大きくなる。そして、この大きなフイラメ
ントパワーを導入することは難しく、その構造も
相当に複雑になることが予想される。他方、外部
加熱によらずに、初期放電により大きな体積の
LaB6陰極を加熱することは難しく、放電のスタ
ートを容易に行うことができない。 Also, assuming that a LaB 6 cathode is used,
If heated externally with a W filament, it will heat up to 40% at 1800℃.
Although it is possible to obtain a large current density of cm 2 or more and satisfies the conditions (2) to (5) above, a large surface area and volume are inevitably required to obtain a large current for a long time. Therefore, the power of the W filament for external heating becomes extremely large. It is difficult to introduce such a large filament power, and the structure is expected to be considerably complicated. On the other hand, a large volume can be generated by initial discharge without external heating.
It is difficult to heat the LaB 6 cathode, making it difficult to start the discharge.
このように、従来のプラズマ生成用放電陰極
は、いずれも欠点を有し、上記の条件を総て充た
すものは存在しなかつた。 As described above, all of the conventional discharge cathodes for plasma generation have drawbacks, and there is no one that satisfies all of the above conditions.
そこで、本発明は、上記の欠点を解消し、長時
間大電流放電を可能にするプラズマ生成用陰極を
提供しようとするものである。 SUMMARY OF THE INVENTION Therefore, the present invention aims to eliminate the above-mentioned drawbacks and provide a cathode for plasma generation that enables long-time, large-current discharge.
（課題を解決するための手段）
本発明は、熱容量の小さな補助陰極と、プラズ
マ流発生方向に垂直な断面がリング形状で、上記
補助陰極の先端近傍を上記リング形状の内部に含
むように該補助陰極に周設された主陰極LaB6と
を有し、該補助陰極の初期放電を集中させ、それ
を利用して主陰極LaB6を加熱し気体中で大電流
放電を可能としたことを特徴とするプラズマ生成
用複合型LaB6陰極である。(Means for Solving the Problems) The present invention includes an auxiliary cathode having a small heat capacity, a ring-shaped cross section perpendicular to the direction of plasma flow generation, and a structure in which the auxiliary cathode is arranged such that the vicinity of the tip thereof is included inside the ring shape. It has a main cathode LaB 6 surrounded by an auxiliary cathode, concentrates the initial discharge of the auxiliary cathode, and uses it to heat the main cathode LaB 6 , making it possible to discharge a large current in the gas. This is a composite type LaB 6 cathode for plasma generation.
（作用）
第１図及び第２図は、本発明の具体例であるプ
ラズマ生成用複合型LaB6陰極の断面図であり、
第３図は、第１図の陰極を用いた放電装置の概念
図である。(Function) FIGS. 1 and 2 are cross-sectional views of a composite LaB 6 cathode for plasma generation, which is a specific example of the present invention,
FIG. 3 is a conceptual diagram of a discharge device using the cathode of FIG. 1.
第１図は、Mo製円筒体７をステンレス製陰極
支持台１に固定し、該円筒体７の先端は中心に孔
を有するＷ製円板９で閉じ、該円筒体７内面に炭
素製支持台８によりリング形状の主陰極LaB6６
を固定し、該円筒体７の後方に気体挿入孔２を備
えたMo製熱シールド４を取り付け、該主陰極６
内にＷ製コイル５が位置するように該コイル５の
後端部を上記熱シールド４で支持する。なお、上
記支持台１には冷却手段３を付設する。 In Figure 1, a Mo cylinder 7 is fixed to a stainless steel cathode support 1, the tip of the cylinder 7 is closed with a W disk 9 having a hole in the center, and a carbon support is attached to the inner surface of the cylinder 7. Ring-shaped main cathode LaB 6 6 with stand 8
is fixed, a Mo heat shield 4 equipped with a gas insertion hole 2 is attached to the rear of the cylindrical body 7, and the main cathode 6 is fixed.
The rear end of the coil 5 is supported by the heat shield 4 so that the coil 5 made of W is located inside. Note that a cooling means 3 is attached to the support stand 1.
第２図は、第１図の陰極において、Ｗ製コイル
５の代わりに、先端部が薄肉のTa製パイプ１０
を用いたものであり、該パイプ１０の孔を気体挿
入孔２としたものであつて、その他の構成は、第
１図と違わないので、説明を省略する。 FIG. 2 shows a cathode in FIG. 1 in which a Ta pipe 10 with a thin tip end is used instead of the W coil 5.
The hole in the pipe 10 is used as the gas insertion hole 2, and the other configuration is the same as that in FIG. 1, so a description thereof will be omitted.
第３図の放電装置は、ガラス製又はセラミツク
製の円筒体１１内に第１図の陰極を収容し、前方
に気体排気口１６を有する中間電極１７及び放電
電極１８を配置し、放電直列抵抗１３及び放電電
源１４と中間電極負荷抵抗１５を配置して放電回
路を形成し、矢印の弱磁場１２の存在下で放電を
行うものである。 The discharge device shown in FIG. 3 houses the cathode shown in FIG. 1 in a cylindrical body 11 made of glass or ceramic, has an intermediate electrode 17 having a gas exhaust port 16 in front, and a discharge electrode 18, and has a discharge series resistance. 13, a discharge power supply 14, and an intermediate electrode load resistor 15 are arranged to form a discharge circuit, and discharge is performed in the presence of a weak magnetic field 12 indicated by an arrow.
第３図の装置でプラズマ放電を行う手順を説明
すると、Mo製の円体内に水素ガスを導入し、放
電開始領域のガス圧力を上げてパツシエンの方則
から短距離で放電電圧を最小にする目的で、円筒
体内を1Torr程度に保つ。そして、プラズマ生成
用複合型LaB6陰極と中間電極との間に50ガウス
程度の弱磁場を発生させ、補助陰極であるＷ製コ
イルに数Ａ程度の小電流放電を開始させて中的に
加熱する。この加熱により、主陰極を1500〜1800
℃に加熱して大電流放電が誘導される。その際
に、2500℃以上に加熱して陰極の寿命に影響を与
えることはない。そして、この大電流放電により
Ｗ製コイルの補助陰極は温度上昇を免れる。ま
た、主陰極円筒体内のガス圧力とプラズマ密度が
高くなつているので、上記数10ガウス程度以下の
弱磁場による電子のマグネトロンカツトオフは、
電子と中性粒子やイオンの衝突で避けられる。中
間電極に負荷抵抗を接続して放電陽極との間に弱
い電場を加えることにより、プラズマ流は、
10-2Torr前後で放電陽極から放出される。 To explain the procedure for performing plasma discharge using the device shown in Figure 3, hydrogen gas is introduced into a circular body made of Mo, the gas pressure in the discharge starting region is increased, and the discharge voltage is minimized over a short distance according to Patsien's law. For this purpose, maintain the inside of the cylinder at around 1 Torr. Then, a weak magnetic field of about 50 Gauss is generated between the composite LaB 6 cathode for plasma generation and the intermediate electrode, and a small current discharge of about a few amperes is started in the W coil, which is the auxiliary cathode, for intermediate heating. do. This heating heats the main cathode to 1500~1800
℃, a large current discharge is induced. At that time, heating above 2500°C will not affect the life of the cathode. Due to this large current discharge, the auxiliary cathode of the W coil is prevented from increasing in temperature. In addition, since the gas pressure and plasma density inside the main cathode cylinder are increasing, the magnetron cutoff of electrons due to a weak magnetic field of several tens of Gauss or less is as follows.
This can be avoided by collisions between electrons and neutral particles or ions. By connecting a load resistor to the intermediate electrode and applying a weak electric field between it and the discharge anode, the plasma flow is
It is emitted from the discharge anode at around 10 -2 Torr.
本発明では、上記のようにＷ製コイルや先端部
が薄肉のTa製パイプ等の、熱容量の小さな補助
陰極をリング形状のLaB6陰極の内部に設置する
ことにより、まず、小電流放電で補助陰極の先端
を集中的に加熱し、次いで、この発熱により、そ
の周囲に配置した上記主陰極を加熱して主放電を
誘導させ、安定した大電流放電を行うもので、こ
の大電流放電に移行した後は補助陰極への通電を
停止することにより、それ以上の温度上昇を回避
するものである。なお、リング形状の主陰極は、
大電流放電を可能にするために表面積を大きくす
る必要があり、第１図及び第２図に示したような
円筒形状が好ましい。 In the present invention, as described above, by installing an auxiliary cathode with a small heat capacity, such as a W coil or a Ta pipe with a thin tip, inside the ring-shaped LaB 6 cathode, we can first assist with small current discharge. The tip of the cathode is heated intensively, and this heat generation then heats the main cathode placed around it to induce a main discharge, resulting in a stable large current discharge, which then shifts to the large current discharge. After that, the power supply to the auxiliary cathode is stopped to avoid further temperature rise. The ring-shaped main cathode is
In order to enable large current discharge, it is necessary to increase the surface area, and a cylindrical shape as shown in FIGS. 1 and 2 is preferable.
このように、本発明のプラズマ生成用複合型陰
極LaB6は、プラズマイオン源として利用するこ
とができる。また、第２の陽極を設けることによ
り、プラズマ電子ビームとして取り出して利用す
ることもできる。 In this way, the composite cathode LaB 6 for plasma generation of the present invention can be used as a plasma ion source. Furthermore, by providing a second anode, it is also possible to extract and use it as a plasma electron beam.
（実施例）
第３図の放電装置を用いてプラズマ放電の実験
を行つた。主陰極として、内径２cm、厚さ2.5mm、
長さ２cmのLaB6円筒体を使用し、補助陰極とし
て、太さ1.4mmのＷ線を約１cmの直径で６回まい
たコイルを使用した。水素を上記円筒体内に導入
し、中間電極の負荷抵抗を８Ωとし、放電電源の
電圧を約400Vに上げたときに放電が開始して数
秒以内に放電電圧が下がつて平衝状態に達した。
この状態で、陰極と中間電極との間は0.6Torr程
度であり、放電陽極の右端で10-2Torr程度であ
り、補助陰極と中間電極との間が約45V、中間電
極と放電陽極との間は約35Vであつた。そして、
中間電極の負荷抵抗には5A程度しか電流が流れ
なかつたが、主陰極からは500A以上の大電流を
長時間放電させることができた。(Example) A plasma discharge experiment was conducted using the discharge apparatus shown in FIG. As the main cathode, the inner diameter is 2 cm, the thickness is 2.5 mm,
A LaB 6 cylindrical body with a length of 2 cm was used, and as an auxiliary cathode, a coil in which W wire with a thickness of 1.4 mm was wound six times with a diameter of about 1 cm was used. When hydrogen was introduced into the cylinder, the load resistance of the intermediate electrode was set to 8Ω, and the voltage of the discharge power source was raised to approximately 400V, the discharge voltage decreased within a few seconds after the discharge started and reached an equilibrium state. .
In this state, the voltage between the cathode and the intermediate electrode is approximately 0.6 Torr, the voltage at the right end of the discharge anode is approximately 10 -2 Torr, the voltage between the auxiliary cathode and the intermediate electrode is approximately 45 V, and the voltage between the intermediate electrode and the discharge anode is approximately 45 V. The voltage between them was about 35V. and,
Although only about 5A of current flowed through the load resistance of the intermediate electrode, a large current of more than 500A could be discharged from the main cathode for a long time.
（発明の効果）
本発明は、上記の構成を採用することにより、
陰極の構造を簡単にすることができ、放電のスタ
ートを容易にし、長時間の大電流放電を可能にし
た。(Effect of the invention) By adopting the above configuration, the present invention has the following features:
The structure of the cathode can be simplified, making it easier to start discharge and enabling long-term, large-current discharge.
第１図及び第２図は本発明の具体例であるプラ
ズマ生成用複合型LaB6陰極の構成図であり、第
３図は第１図の陰極を用いた放電装置の構成図で
ある。図において、１：ステンレス製陰極支持
台、２：気体導入孔、３：冷却手段、４：Mo製
熱シールド、５：Ｗ製コイル、６：主陰極LaB6、
７：Mo製円筒体、８：炭素支持台、９：中心に
孔を有するＷ製円板、１０：Ta製パイプ、１
１：ガラス製またはセラミツク製の円筒体、１
２：弱磁場、１３：放電直列抵抗、１４：放電電
源、１５：中間電極負荷抵抗、１６：気体排気
口、１７：中間電極、１８：放電電極。
1 and 2 are block diagrams of a composite type LaB 6 cathode for plasma generation, which is a specific example of the present invention, and FIG. 3 is a block diagram of a discharge device using the cathode of FIG. 1. In the figure, 1: stainless steel cathode support, 2: gas introduction hole, 3: cooling means, 4: Mo heat shield, 5: W coil, 6: main cathode LaB 6 ,
7: Cylindrical body made of Mo, 8: Carbon support base, 9: Disc made of W with a hole in the center, 10: Pipe made of Ta, 1
1: Cylindrical body made of glass or ceramic, 1
2: Weak magnetic field, 13: Discharge series resistance, 14: Discharge power supply, 15: Intermediate electrode load resistance, 16: Gas exhaust port, 17: Intermediate electrode, 18: Discharge electrode.
Claims (1)
方向に垂直な断面がリング形状で、上記補助陰極
の先端近傍を上記リング形状の内部に含むように
該補助陰極に周設された主陰極LaB6とを有し、
該補助陰極の初期放電を集中させ、それを利用し
て主陰極LaB6を加熱し気体中で大電流放電を可
能としたことを特徴とするプラズマ生成用複合型
LaB6陰極。1. An auxiliary cathode with a small heat capacity, and a main cathode LaB 6 whose cross section perpendicular to the direction of plasma flow generation is ring-shaped, and which is disposed around the auxiliary cathode so that the vicinity of the tip of the auxiliary cathode is included inside the ring shape. has
A composite type for plasma generation characterized by concentrating the initial discharge of the auxiliary cathode and using it to heat the main cathode LaB 6 to enable large current discharge in gas.
LaB6 cathode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5739579A JPS55148337A (en) | 1979-05-10 | 1979-05-10 | Composite type lab6 cathode for plasma generation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5739579A JPS55148337A (en) | 1979-05-10 | 1979-05-10 | Composite type lab6 cathode for plasma generation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS55148337A JPS55148337A (en) | 1980-11-18 |
| JPH0250577B2 true JPH0250577B2 (en) | 1990-11-02 |
Family
ID=13054429
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5739579A Granted JPS55148337A (en) | 1979-05-10 | 1979-05-10 | Composite type lab6 cathode for plasma generation |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55148337A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002155355A (en) * | 2000-11-17 | 2002-05-31 | Chugai Ro Co Ltd | Method for starting pressure-gradient type plasma generator |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63102320A (en) * | 1986-10-20 | 1988-05-07 | Tokyo Electron Ltd | Plasma growing system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5242591A (en) * | 1975-10-01 | 1977-04-02 | Nippon Zeon Co Ltd | Process for preparing acrylonitrile polymers |
-
1979
- 1979-05-10 JP JP5739579A patent/JPS55148337A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5242591A (en) * | 1975-10-01 | 1977-04-02 | Nippon Zeon Co Ltd | Process for preparing acrylonitrile polymers |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002155355A (en) * | 2000-11-17 | 2002-05-31 | Chugai Ro Co Ltd | Method for starting pressure-gradient type plasma generator |
| JP4627365B2 (en) * | 2000-11-17 | 2011-02-09 | 中外炉工業株式会社 | Starting method of pressure gradient type plasma generator |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55148337A (en) | 1980-11-18 |
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