JPH0552617B2 - - Google Patents
Info
- Publication number
- JPH0552617B2 JPH0552617B2 JP26070284A JP26070284A JPH0552617B2 JP H0552617 B2 JPH0552617 B2 JP H0552617B2 JP 26070284 A JP26070284 A JP 26070284A JP 26070284 A JP26070284 A JP 26070284A JP H0552617 B2 JPH0552617 B2 JP H0552617B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- cathode
- impregnated
- electron emission
- thickness
- 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
- 239000010408 film Substances 0.000 claims description 38
- 229910052751 metal Inorganic materials 0.000 claims description 11
- 239000002184 metal Substances 0.000 claims description 11
- 239000010409 thin film Substances 0.000 claims description 9
- 229910052762 osmium Inorganic materials 0.000 claims description 7
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 6
- 239000000758 substrate Substances 0.000 claims description 6
- 239000000956 alloy Substances 0.000 claims description 5
- 229910045601 alloy Inorganic materials 0.000 claims description 5
- 229910052741 iridium Inorganic materials 0.000 claims description 5
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 claims description 5
- 239000010406 cathode material Substances 0.000 claims description 4
- 229910052702 rhenium Inorganic materials 0.000 claims description 4
- 229910052707 ruthenium Inorganic materials 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 3
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 claims description 2
- 238000002844 melting Methods 0.000 claims description 2
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims 1
- WUAPFZMCVAUBPE-UHFFFAOYSA-N rhenium atom Chemical compound [Re] WUAPFZMCVAUBPE-UHFFFAOYSA-N 0.000 claims 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 17
- 239000008188 pellet Substances 0.000 description 6
- 238000010849 ion bombardment Methods 0.000 description 5
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 5
- 229910052721 tungsten Inorganic materials 0.000 description 5
- 239000010937 tungsten Substances 0.000 description 5
- 238000005275 alloying Methods 0.000 description 3
- 150000004645 aluminates Chemical class 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000002356 single layer Substances 0.000 description 3
- 239000002131 composite material Substances 0.000 description 2
- 101150038956 cup-4 gene Proteins 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000003466 welding Methods 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
- H01J1/20—Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment
- H01J1/28—Dispenser-type cathodes, e.g. L-cathode
Landscapes
- Solid Thermionic Cathode (AREA)
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は高電流密度カソードとして用いられる
含浸形カソードに係わり、特にカソード表面にア
ルミナもしくはアルミナを主体とする酸化物から
なる層を付着させ電子放出特性を向上させた含浸
形カソードに関するものである。[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an impregnated cathode used as a high current density cathode. This invention relates to an impregnated cathode with improved characteristics.
高電流密度カソードとして使用される含浸形カ
ソードは、タングステン(W)、モリブデン（Mo）
等の高融点金属の多孔質基体に、Ba−Caアルミ
ネート等の電子放出物質を含浸させて構成され
る。さらに電子放出特性向上のためにカソード表
面に主として貴金属の薄膜を付着させる場合があ
り、特にその有効な材料としてはイリジウム
（Ir）、オスミウム（Os）等が挙げられる（G.E.
Technical Information Series 67−Ｃ−223）。
また、これらを主体とする合金を用いる場合もあ
り（特公昭47−21343号公報）、これらの薄膜は膜
厚を厚くすると電子放出特性が安定化するのに長
時間を要するとともに高価となるなどの問題があ
つた。そのため、薄膜の厚さは、動作中に下地金
属基体材料と合金化して失なわれる時間を考慮し
て必要最小限の程度まで薄くすることが望まし
い。ところが、このように薄膜の厚さを薄くする
と、真空中のわずかに残存するガスによつてカソ
ード表面がイオン衝撃を受け、薄膜がスパツタリ
ングされて消失し、下地金属基板材料との合金化
によつて失なわれるよりもはるかに短かい時間で
電子放出特性が低下する場合がある。
Impregnated cathodes used as high current density cathodes include tungsten (W) and molybdenum (Mo).
It is constructed by impregnating a porous substrate of a high melting point metal such as Ba-Ca aluminate with an electron-emitting substance such as Ba-Ca aluminate. Furthermore, in order to improve electron emission characteristics, a thin film of mainly noble metals is sometimes attached to the cathode surface, and particularly effective materials include iridium (Ir) and osmium (Os) (GE
Technical Information Series 67-C-223).
In addition, alloys mainly composed of these are sometimes used (Japanese Patent Publication No. 47-21343), and when these thin films are thickened, it takes a long time to stabilize the electron emission characteristics and they become expensive. There was a problem. Therefore, it is desirable to reduce the thickness of the thin film to the minimum necessary level in consideration of the time required for alloying with the base metal substrate material during operation. However, when the thickness of the thin film is reduced in this way, the cathode surface is subjected to ion bombardment by the small amount of gas remaining in the vacuum, causing the thin film to sputter and disappear, resulting in alloying with the underlying metal substrate material. In some cases, the electron emission properties deteriorate in a much shorter time than the electron emission characteristics are lost over time.
したがつて本発明は前述した従来の問題点を除
去し、低価格でかつ安定した電子放出特性が得ら
れる含浸形カソードを提供することを目的として
いる。
Therefore, an object of the present invention is to eliminate the above-mentioned conventional problems and to provide an impregnated cathode that is inexpensive and provides stable electron emission characteristics.
このような目的を達成するために本発明による
含浸形カソードは、カソード材料表面にIr、Os、
Ru、Reあるいはこれらの合金からなる単層膜も
しくは複合膜（以下金属膜と称する）を形成した
上にさらに膜厚10〜800Åの範囲でAl2O3もしく
はAl2O3を主体とする酸化物からなる薄膜（以下
Al2O3膜と称する）を付着させて構成するもので
ある。
In order to achieve this purpose, the impregnated cathode according to the present invention has Ir, Os,
After forming a single-layer film or a composite film (hereinafter referred to as metal film) made of Ru, Re, or an alloy thereof, oxidation mainly consisting of Al 2 O 3 or Al 2 O 3 is applied to a film thickness of 10 to 800 Å. A thin film consisting of a substance (hereinafter referred to as
It is constructed by attaching an Al 2 O 3 film).
次に図面を用いて本発明の実施例を詳細に説明
する。
Next, embodiments of the present invention will be described in detail using the drawings.
図は本発明による含浸形カソードを模式的に示
した断面図である。図において、１はカソード材
料としてのペレツトであり、このペレツト１は空
孔率20〜25％のタングステン(W)基板２と空孔３と
から形成されており、この空孔３中にはBa−Ca
アルミネートが含浸されている。そして、このペ
レツト１はタンタル（Ta）カツプ４に装着され、
その後このTaカツプ４はTaスリーブ５にレーザ
溶接により取り付け固定されている。また、カソ
ードペレツト１の表面には厚さ約800Å程度のオ
スミウム（Os）膜６とそのOs膜６上に厚さ約40
Å程度のアルミナ（Al2O3）膜７とが順次被着形
成されている。そして、このカソードは、タング
ステン(W)芯線８にアルミナ（Al2O3）９を被覆し
たヒータ１０により加熱されて電子放出が行なわ
れる。 The figure is a sectional view schematically showing an impregnated cathode according to the present invention. In the figure, numeral 1 is a pellet as a cathode material, and this pellet 1 is formed from a tungsten (W) substrate 2 with a porosity of 20 to 25% and holes 3. −Ca
Impregnated with aluminate. Then, this pellet 1 is attached to a tantalum (Ta) cup 4,
Thereafter, this Ta cup 4 is attached and fixed to the Ta sleeve 5 by laser welding. Further, on the surface of the cathode pellet 1, there is an osmium (Os) film 6 with a thickness of about 800 Å, and on the Os film 6 there is an osmium (Os) film 6 with a thickness of about 40 Å.
An alumina (Al 2 O 3 ) film 7 having a thickness of approximately 1.5 Å is deposited in sequence. This cathode is heated by a heater 10 in which a tungsten (W) core wire 8 is coated with alumina (Al 2 O 3 ) 9 to emit electrons.
このような構成によれば、Os膜６上にAl2O3膜
７を付着形成したことにより、真空中にわずかに
残存するガスのイオン衝撃によるOs膜６の消失
を確実に阻止することができる。 According to this configuration, by depositing the Al 2 O 3 film 7 on the Os film 6, it is possible to reliably prevent the Os film 6 from disappearing due to ion bombardment of the gas slightly remaining in the vacuum. can.
従来、含浸形カソードにおいて、前述したOs
膜６などの金属膜を例えば約5000Å程度と厚く形
成し、最表面にAl2O3膜７を形成しない場合、カ
ソードの動作温度が高く、カソード自体あるいは
周囲からのガス放出が多いために管内真空度が低
い初期の段階で、この金属膜がイオン衝撃によつ
てスパツタされて消失し、金属膜が下地金属材料
との合金化によつて消失するよりもはるかに短時
間に電子放出特性が劣化する場合がある。 Conventionally, in impregnated cathodes, the above-mentioned Os
If the metal film such as the film 6 is formed as thick as about 5000 Å, and the Al 2 O 3 film 7 is not formed on the outermost surface, the operating temperature of the cathode will be high and gas will be released from the cathode itself or the surroundings, causing the inside of the tube to deteriorate. At an early stage when the degree of vacuum is low, this metal film is sputtered and disappears due to ion bombardment, and the electron emission properties are lost much more quickly than when the metal film disappears due to alloying with the underlying metal material. It may deteriorate.
このような現象が発生しなかつた場合において
も、前述したAl2O3膜７をOs膜６上に付着形成す
ることにより、カソード本来の電子放出特性をわ
ずかではあるが改善することができる。 Even if such a phenomenon does not occur, by depositing the aforementioned Al 2 O 3 film 7 on the Os film 6, the inherent electron emission characteristics of the cathode can be improved, albeit slightly.
また、このように構成される含浸形カソードを
ブラウン管に実装して動作させ、電子放出特性を
調べたところ、約1000時間経過後に初期値の約80
％以上の電子放出特性が得られた。比較例として
前述したAl2O3膜７を付着しなかつたカソードを
ブラウン管に実装して同様の試験を行なつたとこ
ろ、初期値の約50％以下に低下していた。 In addition, when an impregnated cathode constructed in this way was mounted on a cathode ray tube and operated, and its electron emission characteristics were examined, it was found that after approximately 1000 hours, the initial value of approximately 80
% or more of electron emission characteristics were obtained. As a comparative example, when a cathode without the Al 2 O 3 film 7 described above was mounted on a cathode ray tube and a similar test was conducted, the value decreased to about 50% or less of the initial value.
なお、前述した実施例において、Al2O3膜７の
膜厚を、約40Å程度としたが、このAl2O3膜７は
Os膜６がイオン衝撃により消失するのを阻止す
るのに十分なほどの厚さ、すなわちイオン衝撃に
耐え得る程度の約10Å以上とし、かつ電子放出特
性に悪影響をおよぼすほどに厚くはない約800Å
以下の範囲内に形成することが必要であり、コス
ト、生産性および安定性等を考慮すると、20〜
200Åの範囲が好ましく、望ましくは20〜100Åの
範囲が好適である。また、Os膜６の厚さを約
5000Åとしたが、このOs膜６の厚さは、薄過ぎ
ると、ペレツト１へ拡散してしまい、また厚すぎ
ると、活性化に時間を要することから、500Å〜
1μmの範囲が好ましく、コスト、生産性および安
定性等を考慮すると、3000〜6000Åの範囲が望ま
しい。 In the above-mentioned embodiment, the thickness of the Al 2 O 3 film 7 was about 40 Å, but this Al 2 O 3 film 7
The thickness should be sufficient to prevent the Os film 6 from disappearing due to ion bombardment, that is, approximately 10 Å or more to withstand ion bombardment, but not so thick as to adversely affect electron emission characteristics, approximately 80 Å.
It is necessary to form within the following range, and considering cost, productivity, stability, etc.
A range of 200 Å is preferred, preferably a range of 20 to 100 Å. In addition, the thickness of the Os film 6 is approximately
However, if the thickness of the Os film 6 is too thin, it will diffuse into the pellet 1, and if it is too thick, it will take time to activate.
A range of 1 μm is preferable, and a range of 3000 to 6000 Å is desirable in consideration of cost, productivity, stability, etc.
なお、前述した実施例においては、カソード材
料表面に形成する金属膜をOs膜とし、さらにこ
の金属膜上に形成する最表面膜としてAl2O3膜を
形成した場合について説明したが、金属膜を例え
ばIr、Ru、Reあるいはこれらの合金からなる単
層膜もしくは多層膜とし、さらにこれらの金属膜
上に形成する最表面膜をAl2O3を主体とする酸化
膜からなる薄膜を付着形成させても前述と全く同
等の効果が得られることは勿論である。 In addition, in the above-mentioned embodiment, the case was explained in which the metal film formed on the surface of the cathode material was an Os film, and the Al 2 O 3 film was further formed as the outermost surface film formed on this metal film. For example, a single layer or multilayer film made of Ir, Ru, Re, or an alloy thereof is formed, and a thin film made of an oxide film mainly composed of Al 2 O 3 is deposited as the outermost film formed on these metal films. Of course, the same effect as described above can be obtained even if this is done.
以上説明したように本発明による含浸形カソー
ドは、カソード材料表面にIr、Os、Ru、Reある
いはこれらの合金からなる単層膜もしくは複合膜
を形成した上にさらに膜厚10〜800Åの範囲で
Al2O3もしくはAl2O3を主体とする酸化物からな
る薄膜を付着形成したことにより、低価格でかつ
安定した電子放出特性が得られるという極めて優
れた効果を有する。
As explained above, the impregnated cathode of the present invention has a single layer or a composite film made of Ir, Os, Ru, Re, or an alloy thereof formed on the surface of the cathode material, and further has a film thickness in the range of 10 to 800 Å.
By depositing a thin film of Al 2 O 3 or an oxide mainly composed of Al 2 O 3 , it has an extremely excellent effect of providing stable electron emission characteristics at low cost.
図は本発明による含浸形カソードの一例を模式
的に示す断面図である。
１……ペレツト、２……タングステン基板、３
……空孔、４……タンタル（Ta）カツプ、５…
…Taスリーブ、６……オスミウム（Os）膜、７
……アルミナ（Al2O3）膜、８……タングステン
(W)芯線、９……アルミナ（Al2O3）、１０……ヒ
ータ。
The figure is a sectional view schematically showing an example of an impregnated cathode according to the present invention. 1... Pellet, 2... Tungsten substrate, 3
...Vacancy, 4...Tantalum (Ta) cup, 5...
...Ta sleeve, 6...Osmium (Os) membrane, 7
...Alumina (Al 2 O 3 ) film, 8...Tungsten
(W) Core wire, 9...Alumina (Al 2 O 3 ), 10... Heater.
Claims (1)
浸させた含浸形カソードにおいて、カソード材料
の表面に、イリジウム、オスミウム、ルテニウ
ム、レニウムあるいはこれらの合金からなる金属
膜を形成し、さらにその最表面に10〜800Åの範
囲でアルミナあるいはアルミナを主体とする酸化
物からなる薄膜を付着させたことを特徴とする含
浸形カソード。1. In an impregnated cathode in which a porous substrate made of a high-melting point metal is impregnated with an electron-emitting substance, a metal film made of iridium, osmium, ruthenium, rhenium, or an alloy thereof is formed on the surface of the cathode material, and the outermost surface An impregnated cathode characterized by having a thin film of alumina or an oxide mainly composed of alumina adhered thereto in a range of 10 to 800 Å.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59260702A JPS61140019A (en) | 1984-12-12 | 1984-12-12 | Impregnated cathode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59260702A JPS61140019A (en) | 1984-12-12 | 1984-12-12 | Impregnated cathode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61140019A JPS61140019A (en) | 1986-06-27 |
| JPH0552617B2 true JPH0552617B2 (en) | 1993-08-05 |
Family
ID=17351582
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59260702A Granted JPS61140019A (en) | 1984-12-12 | 1984-12-12 | Impregnated cathode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61140019A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2567853B (en) * | 2017-10-26 | 2020-07-29 | Isotopx Ltd | Gas-source mass spectrometer comprising an electron source |
-
1984
- 1984-12-12 JP JP59260702A patent/JPS61140019A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61140019A (en) | 1986-06-27 |
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