US3275865A - Field emission tube with low temperature gas adsorption - Google Patents
Field emission tube with low temperature gas adsorption Download PDFInfo
- Publication number
- US3275865A US3275865A US308131A US30813163A US3275865A US 3275865 A US3275865 A US 3275865A US 308131 A US308131 A US 308131A US 30813163 A US30813163 A US 30813163A US 3275865 A US3275865 A US 3275865A
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- US
- United States
- Prior art keywords
- envelope
- anode
- cathode
- field emission
- tube
- 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
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J21/00—Vacuum tubes
- H01J21/02—Tubes with a single discharge path
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J17/00—Gas-filled discharge tubes with solid cathode
- H01J17/02—Details
- H01J17/20—Selection of substances for gas fillings; Specified operating pressures or temperatures
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
- H01J19/74—Cooling arrangements
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
- H01J5/02—Vessels; Containers; Shields associated therewith; Vacuum locks
- H01J5/12—Double-wall vessels or containers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
- H01J7/24—Cooling arrangements; Heating arrangements; Means for circulating gas or vapour within the discharge space
-
- 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
- H01J9/38—Exhausting, degassing, filling, or cleaning vessels
Definitions
- the invention relates to a device employing an electric discharge tube in which the cathode consists of a conductive part having a very small radius of curvature on which the field of the anode is operative, a field emission cathode which is not heated.
- the invention further relates to an electric discharge tube for such a device and to a method of manufacturing such a discharge tube.
- a difiiculty with the small dimensions is that the presence of an exhaust tube increases the dimensions disproportionately.
- solder a discharge tube together in vacuum from the component parts, this has the disadvantage for a tube with a field emission cathode that soldering material evaporates at the required high soldering temperature and precipitates on the cathode. As a result of this, these cathodes usually become useless.
- the object of the invention is to provide a device and :a discharge tube for such a device which do not have the above drawbacks.
- the discharge tube is located in a space having such a low temperature that the residual gas possibly present in adsorbed to such an extent that the requirements for field emission from a non-heated cathode are satisfied, while in the tube argon is available with a pressure of a few tens torr at room temperature and this tube consists of metal and ceramic parts soldered together.
- the tube according to the invention is soldered together in an argon atmosphere at a pressure of the order of ten torr, which has the advantage that the possible evaporation of the solder is no longer harmful.
- the argon may first have been used as a cleaning gas.
- the argon of low pressure left in the tube after soldering does not disturb the operation of the tube at the low temperature, for example that of liquid helium, because the gas which is condensed then has a sufiiciently low vapor pressure.
- FIG. 1 is a cross-sectional view of a diode according to the invention
- FIG. 2 is a controllable discharge tube
- FIG. 3 diagrammatically shows a device employing a number oi the tubes according to the invention.
- reference numeral 1 is a cylinder of pure aluminum oxide against which the cathode plate 2 and the anode plate 3 are soldered by means of soldering edges 4 and 5 respectively.
- the plates consist of molybdenum. '1 hey are soldered to the cylinder metallized with molybdenum manganese powder by means of silver.
- a tungsten wire 6 of 0.1 mm. thickness is welded to the cathode plate 2, the tip 7 of said wire having a radius of curvature 2 x 10* mm. The distance from the tip 7 to the plate 3 is 0.3 mm.
- the diameter of the cathode and anode plates is 3 mms. and the height of the cylinder is 4 mms.
- the tube is sealed by soldering after degassing in an atmosphere of argon of 20 torr. If the tube is dipped in liquid helium, a current of 10,ua. may be obtained at an anode voltage of 0.75 kv.
- the cathode 6, 7 is arranged in the same manner as in the case of FIG. 1.
- the tip of the cathode is located opposite an aperture 8 in the plate 9 on which, in the direction of movement of the electrons, follow the perforated plate 10 and finally the anode 11.
- the cathode plate 2 and the plates 9, 10 and 11 are insulated from one another by the cylinders of aluminum oxide 12, 13, 14 soldered, thereto in a vacuum-tight manner, While on the outside cylinders 15 and 16 are soldered so as to decrease the tension in the soldering points.
- the plate 9, as was the case in the tube of FIG. 1, has a voltage of 0.75 kv. with respect to the cathode.
- the plate 10 is approximately at cathode potential. With this plate the electron current, which is accelerated by the plate 9 operating as the first anode, may be controlled, as a result of which consequently the anode current is determined.
- the cryostat is diagrammatically shown by means of the single Dewar flask 17 which contains liquid helium 18 nearly to the rim.
- components 19 are located each comprising a number of tubes 19 of the type described in FIG. 2.
- the electric supply wires 20 for the tubes 19 are passed through the neck of the Dewar flask.
- the passive switching elements are located in the components.
- An electric discharge device comprising an envelope containing an anode and a cathode, said cathode comprising a wire-like element having one end spaced from the anode with a relatively small radius of curvature whereby electrons are emitted from said cathode by the action of an electric field produced by the anode, said envelope comprising metal portions separated by and joined to ceramic portions by a solder material, an argon atmosphere in said envelope at a pressure of the order of ten torr at room temperature, and means to cool said envelope to a temperature substantially below room temperature and at which the argon gas is substantially adsorbed by said envelope.
- cooling means is a vessel substantially filled with liquid helium surrounding said envelope.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
- Solid Thermionic Cathode (AREA)
Description
P 7, 1966 A. G. J. VAN OOSTROM ET AL 3,275,865
FIELD EMISSION TUBE-WITH LOW TEMPERATURE GAS ABSORPTION Filed Sept. 11, 1963 FIG.2]
INVENTOR ANTDNIUS G.J. OOSTROM A LBERTU S V MA f imwa United States Patent 3,275,865 FIELD EMISSION TUBE WITH LOW TEMPERA- TURE GAS ADSORPTION Antonius Gerardus Johannes van Oostrom and Albertus Venema, Emmasingel, Eindhoven, Netherlands, assignors to North American Philips Company, Inc., New York, N .Y., a corporation of Delaware Filed Sept. 11, 1963, Ser. No. 308,131 Claims priority, application Netherlands, Sept. 11, 1962, 283,116/ 62 2 Claims. (Cl. 313-11) The invention relates to a device employing an electric discharge tube in which the cathode consists of a conductive part having a very small radius of curvature on which the field of the anode is operative, a field emission cathode which is not heated. The invention further relates to an electric discharge tube for such a device and to a method of manufacturing such a discharge tube.
As a result of their small proportions, high current densities and the absence of a heating element field emission cathodes have the advantage that the dimensions of a discharge tube may be very small. In this case, the anode voltage need not be extremely high to obtain nevertheless suflicient field strength at the cathode. As a result of this, such tubes would be highly suitable, for example, for assembly in large numbers in compact logical networks.
A drawback of such tubes, however, is that the required vacuum is so extreme, namely pressures lower than torr, that this is hardly obtainable with the normal means. Even if right after the manufacture of a tube, the pressure would be sufliciently low, the pressure would soon have become too high, in particular as a result of the small volume of such small tubes with respect to the area.
A difiiculty with the small dimensions is that the presence of an exhaust tube increases the dimensions disproportionately. Although it is possible to solder a discharge tube together in vacuum from the component parts, this has the disadvantage for a tube with a field emission cathode that soldering material evaporates at the required high soldering temperature and precipitates on the cathode. As a result of this, these cathodes usually become useless.
The object of the invention is to provide a device and :a discharge tube for such a device which do not have the above drawbacks.
In a device with an electric discharge tube in which the cathode consists of a conductive part with a very small radius 'of curvature on which the electric field is operative, according to the invention, the discharge tube is located in a space having such a low temperature that the residual gas possibly present in adsorbed to such an extent that the requirements for field emission from a non-heated cathode are satisfied, while in the tube argon is available with a pressure of a few tens torr at room temperature and this tube consists of metal and ceramic parts soldered together.
The tube according to the invention is soldered together in an argon atmosphere at a pressure of the order of ten torr, which has the advantage that the possible evaporation of the solder is no longer harmful. The argon may first have been used as a cleaning gas. The argon of low pressure left in the tube after soldering does not disturb the operation of the tube at the low temperature, for example that of liquid helium, because the gas which is condensed then has a sufiiciently low vapor pressure.
In order that the invention may be readily carried into effect, an embodiment thereof will now be described "ice more fully, by way of example, with reference to the accompanying drawing, in which:
FIG. 1 is a cross-sectional view of a diode according to the invention,
FIG. 2 is a controllable discharge tube, and
FIG. 3 diagrammatically shows a device employing a number oi the tubes according to the invention.
In FIG. 1, reference numeral 1 is a cylinder of pure aluminum oxide against which the cathode plate 2 and the anode plate 3 are soldered by means of soldering edges 4 and 5 respectively. The plates consist of molybdenum. '1 hey are soldered to the cylinder metallized with molybdenum manganese powder by means of silver. A tungsten wire 6 of 0.1 mm. thickness is welded to the cathode plate 2, the tip 7 of said wire having a radius of curvature 2 x 10* mm. The distance from the tip 7 to the plate 3 is 0.3 mm. The diameter of the cathode and anode plates is 3 mms. and the height of the cylinder is 4 mms. The tube is sealed by soldering after degassing in an atmosphere of argon of 20 torr. If the tube is dipped in liquid helium, a current of 10,ua. may be obtained at an anode voltage of 0.75 kv.
In FIG. 2, the cathode 6, 7 is arranged in the same manner as in the case of FIG. 1. The tip of the cathode is located opposite an aperture 8 in the plate 9 on which, in the direction of movement of the electrons, follow the perforated plate 10 and finally the anode 11. The cathode plate 2 and the plates 9, 10 and 11 are insulated from one another by the cylinders of aluminum oxide 12, 13, 14 soldered, thereto in a vacuum-tight manner, While on the outside cylinders 15 and 16 are soldered so as to decrease the tension in the soldering points.
The plate 9, as was the case in the tube of FIG. 1, has a voltage of 0.75 kv. with respect to the cathode. The plate 10 is approximately at cathode potential. With this plate the electron current, which is accelerated by the plate 9 operating as the first anode, may be controlled, as a result of which consequently the anode current is determined.
In FIG. 3, the cryostat is diagrammatically shown by means of the single Dewar flask 17 which contains liquid helium 18 nearly to the rim. In this liquid helium, components 19 are located each comprising a number of tubes 19 of the type described in FIG. 2. The electric supply wires 20 for the tubes 19 are passed through the neck of the Dewar flask. The passive switching elements are located in the components.
What is claimed is:
1. An electric discharge device comprising an envelope containing an anode and a cathode, said cathode comprising a wire-like element having one end spaced from the anode with a relatively small radius of curvature whereby electrons are emitted from said cathode by the action of an electric field produced by the anode, said envelope comprising metal portions separated by and joined to ceramic portions by a solder material, an argon atmosphere in said envelope at a pressure of the order of ten torr at room temperature, and means to cool said envelope to a temperature substantially below room temperature and at which the argon gas is substantially adsorbed by said envelope.
2. An electric discharge device as defined in claim 1 in which the cooling means is a vessel substantially filled with liquid helium surrounding said envelope.
No references cited.
JAMES W. LAWRENCE, Primary Examiner.
R. SEGAL, Assistant Examiner.
Claims (1)
1. AN ELECTRIC DISCHARGE DEVICE COMPRISING AN ENVELOPE CONTAINING AN ANODE AND A CATHODE, SAID CATHOD COMPRISING A WIRE-LIKE ELEMENT HAVING ONE END SPACED FROM THE ANODE WITH A RELATIVELY SMALL RADIUS OF CURVATURE WHEREBY ELECTRONS ARE EMITTED FROM SAID CATHOD BY THE ACTION OF AN ELECTRIC FIELD PRODUCED BY THE ANODE, SAID ENVELOPE COMPRISING METAL PORTIONS SEPARATED BY SAID JOINED TO CERAMIC PORTIONS BY A SOLDER MATERIAL, AN ARGON ATMOSPHERE IN SAID ENVELOPE AT A PRESSURE OF THE COOL SAID ENVELOPE TO A TEMPERATURE SUBSTANTIALLY BELOW ROOM TEMPERATURE AND AT WHICH THE ARGON GAS IS SUBSTANTIALLY ADSORBED BY SAID ENVELOPE.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL283116A NL113462C (en) | 1962-09-11 | 1962-09-11 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3275865A true US3275865A (en) | 1966-09-27 |
Family
ID=19754096
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US308131A Expired - Lifetime US3275865A (en) | 1962-09-11 | 1963-09-11 | Field emission tube with low temperature gas adsorption |
Country Status (7)
Country | Link |
---|---|
US (1) | US3275865A (en) |
BE (1) | BE637187A (en) |
CH (1) | CH424001A (en) |
DE (1) | DE1280422B (en) |
DK (1) | DK108368C (en) |
GB (1) | GB1019136A (en) |
NL (1) | NL113462C (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5698942A (en) * | 1996-07-22 | 1997-12-16 | University Of North Carolina | Field emitter flat panel display device and method for operating same |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AT160477B (en) * | 1937-02-16 | 1941-06-10 | Loewe Radio Ag | Electron amplifier with photocathode. |
DE689830C (en) * | 1937-05-15 | 1940-04-04 | Siemens & Halske Akt Ges | Process for improving the emission properties of cold tip cathodes |
-
0
- BE BE637187D patent/BE637187A/xx unknown
-
1962
- 1962-09-11 NL NL283116A patent/NL113462C/xx active
-
1963
- 1963-09-06 GB GB35287/63A patent/GB1019136A/en not_active Expired
- 1963-09-07 DE DEN23715A patent/DE1280422B/en active Pending
- 1963-09-07 DK DK424263AA patent/DK108368C/en active
- 1963-09-09 CH CH1111763A patent/CH424001A/en unknown
- 1963-09-11 US US308131A patent/US3275865A/en not_active Expired - Lifetime
Non-Patent Citations (1)
Title |
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None * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5698942A (en) * | 1996-07-22 | 1997-12-16 | University Of North Carolina | Field emitter flat panel display device and method for operating same |
Also Published As
Publication number | Publication date |
---|---|
GB1019136A (en) | 1966-02-02 |
DE1280422B (en) | 1968-10-17 |
BE637187A (en) | |
CH424001A (en) | 1966-11-15 |
DK108368C (en) | 1967-11-27 |
NL113462C (en) | 1966-12-10 |
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