US3833494A - Method of manufacturing a lanthanum hexaboride-activated cathode for an electric discharge tube - Google Patents
Method of manufacturing a lanthanum hexaboride-activated cathode for an electric discharge tube Download PDFInfo
- Publication number
- US3833494A US3833494A US00356620A US35662073A US3833494A US 3833494 A US3833494 A US 3833494A US 00356620 A US00356620 A US 00356620A US 35662073 A US35662073 A US 35662073A US 3833494 A US3833494 A US 3833494A
- Authority
- US
- United States
- Prior art keywords
- lanthanum hexaboride
- manufacturing
- electric discharge
- discharge tube
- layer
- 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
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes
- H01J9/042—Manufacture, activation of the emissive part
Definitions
- the invention relates to a method of manufacturing a cathode for an electric discharge tube in which a layer of lanthanum hexaboride is cataphoretically provided on a rhenium support and is sintered.
- the invention furthermore relates to a cathode manufactured in this manner.
- the cataphoretically provided layer is slowly heated to a temperature of l,500 to l,550C and maintained at said final temperature for maximum 30 seconds until a smooth and shining surface is obtained, after which a second layer of lanthanum hexaboride is cataphoretically provided and also heated to a temperature of 1,500 to l,550C and maintained at said temperature for maximum 2 minutes.
- a layer of rhenium boride is formed all over the surface of the rhenium wire and rhenium wire as a result of excessive boride formation ing example.
- 1 denotes a part of a hard glass bottom in which two wires 2 and 3 of an iron-nickel-cobalt alloy are present.
- a rhenium wire 4 of 0.18 mm diameter is welded to the lead-in wires 2 and 3. After firing the rhenium wire in hydrogen gas at 1,600C for 2 minutes, it is covered from a lanthanum boride suspension (unpurified LaB with a 50 p. thick layer. Said layer is heated for 5 minutes and sintered in hydrogen at 1,530C for 15 seconds. The layer becomes smooth and shining. A 20 microns thick layer of lanthanum hexaboride is then cataphoretically provided, said layer being sintered in hydrogen at l,550C for 2 minutes.
- the cathode After sealing the bottom 1 in a tube and after evacuation thereof, the cathode is degassed at 1,600C for a few seconds. The cathode is then activated at 1,500C for 5 to 30 minutes.
- the saturation emission (measured with pulses) is 10 Alcm
- the life at said temperature is more than 8,000 hours.
- the cathodes according to the invention are suitable for use in high voltage apparatus such as X-ray tubes, rectifier tubes and also in electron beam welding apparatus, electron microscopes and the like, in which comparatively poor vacuum conditions occur and which cathodes are exposed to air repeated times.
- high voltage apparatus such as X-ray tubes, rectifier tubes and also in electron beam welding apparatus, electron microscopes and the like, in which comparatively poor vacuum conditions occur and which cathodes are exposed to air repeated times.
- said cathodes are also suitable.
- a method of manufacturing a cathode for an electric discharge tube in which a layer of lanthanum hexaboride is cataphoretically provided on a rhenium support and sintered characterized in that the cataphoretically provided layer is slowly heated to a temperature of l,500 to l,550C and maintained at said final temperature formaximum 30 seconds until a smooth and shining surface is obtained, after which a second layer of lanthanum hexaboride is cataphoretically provided and also heated to a temperature of l,500 to l,550C and maintained at said temperature for maximum 2 minutes.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL7207275A NL167796C (nl) | 1972-05-30 | 1972-05-30 | Werkwijze voor het vervaardigen van een met lanthaanhexaboride geactiveerde kathode voor een elektrische ontladingsbuis. |
Publications (1)
Publication Number | Publication Date |
---|---|
US3833494A true US3833494A (en) | 1974-09-03 |
Family
ID=19816153
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00356620A Expired - Lifetime US3833494A (en) | 1972-05-30 | 1973-05-02 | Method of manufacturing a lanthanum hexaboride-activated cathode for an electric discharge tube |
Country Status (9)
Country | Link |
---|---|
US (1) | US3833494A (sv) |
JP (1) | JPS5524224B2 (sv) |
CA (1) | CA994280A (sv) |
CH (1) | CH574677A5 (sv) |
DE (1) | DE2325273C3 (sv) |
FR (1) | FR2186725B1 (sv) |
GB (1) | GB1378620A (sv) |
NL (1) | NL167796C (sv) |
SE (1) | SE382886B (sv) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5128475A (ja) * | 1974-09-04 | 1976-03-10 | Hitachi Ltd | Magunetoroninkyokukotai |
JPS51118362A (en) * | 1975-04-10 | 1976-10-18 | Natl Inst For Res In Inorg Mater | Heat electon radiating cathode |
JPS5231652A (en) * | 1975-09-04 | 1977-03-10 | Natl Inst For Res In Inorg Mater | Electron microscope |
JPS5231651A (en) * | 1975-09-04 | 1977-03-10 | Natl Inst For Res In Inorg Mater | Scan-type electron microscope |
US4019081A (en) * | 1974-10-25 | 1977-04-19 | Bbc Brown Boveri & Company Limited | Reaction cathode |
US4054946A (en) * | 1976-09-28 | 1977-10-18 | Bell Telephone Laboratories, Incorporated | Electron source of a single crystal of lanthanum hexaboride emitting surface of (110) crystal plane |
US4055780A (en) * | 1975-04-10 | 1977-10-25 | National Institute For Researches In Inorganic Materials | Thermionic emission cathode having a tip of a single crystal of lanthanum hexaboride |
US4482839A (en) * | 1981-05-29 | 1984-11-13 | Denki Kagaku Kogyo Kabushiki Kaisha | Thermionic emission cathode and preparation thereof |
US5142652A (en) * | 1990-08-20 | 1992-08-25 | Siemens Aktiengesellschaft | X-ray arrangement comprising an x-ray radiator having an elongated cathode |
US5170422A (en) * | 1990-08-20 | 1992-12-08 | Siemens Aktiengesellschaft | Electron emitter for an x-ray tube |
EP1983546A1 (en) * | 2007-04-20 | 2008-10-22 | PANalytical B.V. | X-ray cathode and tube |
US20100301736A1 (en) * | 2007-11-30 | 2010-12-02 | Toshiyuki Morishita | Electron emitting source and manufacturing method of electron emitting source |
US20150002009A1 (en) * | 2012-07-03 | 2015-01-01 | National Institute For Materials Science | Metal hexaboride cold field emitter, method of fabricating same, and electron gun |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2117795A (en) * | 1982-04-06 | 1983-10-19 | Standard Telephones Cables Ltd | Fabricating capacitors; forming ceramic films |
GB8611967D0 (en) * | 1986-05-16 | 1986-10-29 | English Electric Valve Co Ltd | Directly heated cathodes |
JPS6489242A (en) * | 1987-09-30 | 1989-04-03 | Mitsubishi Electric Corp | Electrode for discharge light source |
DE4026297A1 (de) * | 1990-08-20 | 1992-02-27 | Siemens Ag | Roentgenanordnung |
DE4026300A1 (de) * | 1990-08-20 | 1992-02-27 | Siemens Ag | Elektronenemitter einer roentgenroehre |
DE4026298A1 (de) * | 1990-08-20 | 1992-02-27 | Siemens Ag | Roentgenroehre mit einem elektronenemitter |
DE10245392B3 (de) * | 2002-09-28 | 2004-01-08 | Vtd Vakuumtechnik Dresden Gmbh | Rohrförmige Hohlkathode für hohe elektrische Leistungen |
CN104223613B (zh) | 2014-09-26 | 2016-09-28 | 京东方科技集团股份有限公司 | 智能手环显示控制系统及智能手环 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3312856A (en) * | 1963-03-26 | 1967-04-04 | Gen Electric | Rhenium supported metallic boride cathode emitters |
US3498897A (en) * | 1967-07-25 | 1970-03-03 | Ford Motor Co | Method for manufacturing multilayered product |
US3630770A (en) * | 1969-04-30 | 1971-12-28 | Gen Electric | Method for fabricating lanthanum boride cathodes |
-
1972
- 1972-05-30 NL NL7207275A patent/NL167796C/xx not_active IP Right Cessation
-
1973
- 1973-05-02 US US00356620A patent/US3833494A/en not_active Expired - Lifetime
- 1973-05-18 DE DE2325273A patent/DE2325273C3/de not_active Expired
- 1973-05-24 CA CA172,130A patent/CA994280A/en not_active Expired
- 1973-05-25 SE SE7307402A patent/SE382886B/sv unknown
- 1973-05-25 GB GB2515673A patent/GB1378620A/en not_active Expired
- 1973-05-25 CH CH755173A patent/CH574677A5/xx not_active IP Right Cessation
- 1973-05-26 JP JP5825873A patent/JPS5524224B2/ja not_active Expired
- 1973-05-30 FR FR7319645A patent/FR2186725B1/fr not_active Expired
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3312856A (en) * | 1963-03-26 | 1967-04-04 | Gen Electric | Rhenium supported metallic boride cathode emitters |
US3498897A (en) * | 1967-07-25 | 1970-03-03 | Ford Motor Co | Method for manufacturing multilayered product |
US3630770A (en) * | 1969-04-30 | 1971-12-28 | Gen Electric | Method for fabricating lanthanum boride cathodes |
Non-Patent Citations (1)
Title |
---|
L. Favreau, Cataphoretic Coating Lanthanum Boride on Rhenium Filaments, Rev. Sci. Inst., Vol. 36, pages 856 857, (1965). * |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5128475A (ja) * | 1974-09-04 | 1976-03-10 | Hitachi Ltd | Magunetoroninkyokukotai |
US4019081A (en) * | 1974-10-25 | 1977-04-19 | Bbc Brown Boveri & Company Limited | Reaction cathode |
JPS6040133B2 (ja) * | 1975-04-10 | 1985-09-09 | 科学技術庁無機材質研究所長 | 熱電子放射用陰極の製造方法 |
US4055780A (en) * | 1975-04-10 | 1977-10-25 | National Institute For Researches In Inorganic Materials | Thermionic emission cathode having a tip of a single crystal of lanthanum hexaboride |
JPS51118362A (en) * | 1975-04-10 | 1976-10-18 | Natl Inst For Res In Inorg Mater | Heat electon radiating cathode |
JPS5231651A (en) * | 1975-09-04 | 1977-03-10 | Natl Inst For Res In Inorg Mater | Scan-type electron microscope |
JPS5231652A (en) * | 1975-09-04 | 1977-03-10 | Natl Inst For Res In Inorg Mater | Electron microscope |
US4054946A (en) * | 1976-09-28 | 1977-10-18 | Bell Telephone Laboratories, Incorporated | Electron source of a single crystal of lanthanum hexaboride emitting surface of (110) crystal plane |
US4482839A (en) * | 1981-05-29 | 1984-11-13 | Denki Kagaku Kogyo Kabushiki Kaisha | Thermionic emission cathode and preparation thereof |
US5142652A (en) * | 1990-08-20 | 1992-08-25 | Siemens Aktiengesellschaft | X-ray arrangement comprising an x-ray radiator having an elongated cathode |
US5170422A (en) * | 1990-08-20 | 1992-12-08 | Siemens Aktiengesellschaft | Electron emitter for an x-ray tube |
EP1983546A1 (en) * | 2007-04-20 | 2008-10-22 | PANalytical B.V. | X-ray cathode and tube |
US20100301736A1 (en) * | 2007-11-30 | 2010-12-02 | Toshiyuki Morishita | Electron emitting source and manufacturing method of electron emitting source |
US8456076B2 (en) * | 2007-11-30 | 2013-06-04 | Denki Kagaku Kogyo Kabushiki Kaisha | Electron emitting source and manufacturing method of electron emitting source |
US20150002009A1 (en) * | 2012-07-03 | 2015-01-01 | National Institute For Materials Science | Metal hexaboride cold field emitter, method of fabricating same, and electron gun |
US8952605B2 (en) * | 2012-07-03 | 2015-02-10 | National Institute For Materials Science | Metal hexaboride cold field emitter, method of fabricating same, and electron gun |
Also Published As
Publication number | Publication date |
---|---|
SE382886B (sv) | 1976-02-16 |
GB1378620A (en) | 1974-12-27 |
CA994280A (en) | 1976-08-03 |
FR2186725B1 (sv) | 1976-09-17 |
FR2186725A1 (sv) | 1974-01-11 |
JPS5524224B2 (sv) | 1980-06-27 |
NL167796B (nl) | 1981-08-17 |
JPS4944661A (sv) | 1974-04-26 |
NL167796C (nl) | 1982-01-18 |
DE2325273B2 (de) | 1980-09-04 |
NL7207275A (sv) | 1973-12-04 |
CH574677A5 (sv) | 1976-04-15 |
DE2325273C3 (de) | 1981-07-09 |
DE2325273A1 (de) | 1973-12-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3833494A (en) | Method of manufacturing a lanthanum hexaboride-activated cathode for an electric discharge tube | |
US4325000A (en) | Low work function cathode | |
US1794810A (en) | Incandescent cathode for electric discharge tubes | |
US4515528A (en) | Hydrocarbon getter pump | |
US2041802A (en) | Electron emitter | |
US3823453A (en) | Method of manufacturing an indirectly heated cathode and cathode manufactured according to this method | |
US2497110A (en) | Method of making electrodes | |
US3041209A (en) | Method of making a thermionic cathode | |
US3284657A (en) | Grain-oriented thermionic emitter for electron discharge devices | |
US3737709A (en) | Gas discharge tube comprising mercury vapor and provided with a getter | |
US3492598A (en) | Method for processing gas discharge devices | |
US2275886A (en) | Process of activating cathodes | |
US3846006A (en) | Method of manufacturing of x-ray tube having thoriated tungsten filament | |
US4200555A (en) | Low work function hexaboride electron source | |
US2417460A (en) | Nonemissive electrode for electron tube and method of making the same | |
US3283195A (en) | Cold-cathode glow-discharge tube | |
US3721848A (en) | Camera tube having photoconductive lead monoxide layer on silicon carbide signal plate | |
US3495120A (en) | Microheating elements,more particularly for cathodes of electron tubes | |
JP2710700B2 (ja) | 含浸形陰極の製造法及びこの方法によって得られる陰極 | |
US1954189A (en) | Electric discharge tube | |
EP0263483B2 (en) | Hot cathode in wire form | |
US4231627A (en) | Electron beam tube | |
JPS58164129A (ja) | 硼化デイスペンサ陰極の製造方法 | |
US3113370A (en) | Method of making cathode | |
US2995674A (en) | Impregnated cathodes |