US3312856A - Rhenium supported metallic boride cathode emitters - Google Patents
Rhenium supported metallic boride cathode emitters Download PDFInfo
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- US3312856A US3312856A US268107A US26810763A US3312856A US 3312856 A US3312856 A US 3312856A US 268107 A US268107 A US 268107A US 26810763 A US26810763 A US 26810763A US 3312856 A US3312856 A US 3312856A
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- cathode
- rhenium
- support
- wire
- thermionic
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- WUAPFZMCVAUBPE-UHFFFAOYSA-N rhenium atom Chemical compound [Re] WUAPFZMCVAUBPE-UHFFFAOYSA-N 0.000 title claims description 34
- 229910052702 rhenium Inorganic materials 0.000 title claims description 27
- 239000000463 material Substances 0.000 claims description 21
- 229910052746 lanthanum Inorganic materials 0.000 description 19
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 19
- 229910052751 metal Inorganic materials 0.000 description 13
- 239000002184 metal Substances 0.000 description 13
- 239000011248 coating agent Substances 0.000 description 12
- 238000000576 coating method Methods 0.000 description 12
- 238000010438 heat treatment Methods 0.000 description 7
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical group [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 6
- 229910001122 Mischmetal Inorganic materials 0.000 description 6
- 210000003414 extremity Anatomy 0.000 description 5
- 229910052761 rare earth metal Inorganic materials 0.000 description 5
- 150000002910 rare earth metals Chemical class 0.000 description 5
- 238000009792 diffusion process Methods 0.000 description 4
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 4
- 229910052721 tungsten Inorganic materials 0.000 description 4
- 239000010937 tungsten Substances 0.000 description 4
- 238000003466 welding Methods 0.000 description 4
- ZSLUVFAKFWKJRC-IGMARMGPSA-N 232Th Chemical compound [232Th] ZSLUVFAKFWKJRC-IGMARMGPSA-N 0.000 description 3
- 229910052776 Thorium Inorganic materials 0.000 description 3
- 229910052770 Uranium Inorganic materials 0.000 description 3
- 229910052796 boron Inorganic materials 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000003870 refractory metal Substances 0.000 description 3
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- 229910052788 barium Inorganic materials 0.000 description 2
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 238000010422 painting Methods 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229910052712 strontium Inorganic materials 0.000 description 2
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 2
- 229910000521 B alloy Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229940072049 amyl acetate Drugs 0.000 description 1
- PGMYKACGEOXYJE-UHFFFAOYSA-N anhydrous amyl acetate Natural products CCCCCOC(C)=O PGMYKACGEOXYJE-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 150000001639 boron compounds Chemical class 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000005538 encapsulation Methods 0.000 description 1
- MNWFXJYAOYHMED-UHFFFAOYSA-M heptanoate Chemical compound CCCCCCC([O-])=O MNWFXJYAOYHMED-UHFFFAOYSA-M 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 210000001364 upper extremity Anatomy 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Images
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
- H01J1/14—Solid thermionic cathodes characterised by the material
- H01J1/148—Solid thermionic cathodes characterised by the material with compounds having metallic conductive properties, e.g. lanthanum boride, as an emissive material
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- Solid Thermionic Cathode (AREA)
Description
April 4, 1967 J. M. LAFFERTY ETAL 3,
RHENIUM SUPPORTED METALLIC BORIDE CATHODE EMITTERS Filed Marbh 26, 1963 Fig.5.
lm/amors James M. Lafferfy William R. Grams,
by (FM United States Patent 3,312,856 RHENIUM SUPPORTED METALLIC BORIDE CATHODE EMITTERS James M. Lafl'erty, Schenectady, and William R. Grams,
Ballston Spa, N.Y., assignors to General Electric Company, a corporation of New York Filed Mar. 26, 1963, Ser. No. 268,107 7 Claims. (Cl. 313-346) This invention relates generally to improved cathodes for electron discharge devices and more particularly pertains to such cathodes having an improved support for metallic boride emitters.
The borides of certain metals provide e-miters having desirable properties which are in general superior to those of other known emitters. For example, emitters constituted of the borides of the alkaline earth metals, rare earth metals (of the group having atomic numbers 57 through 71), thorium and uranium are very desirable. This is clearly pointed out in US. Patent No. 2,639,399 to J. M. Lafferty.
As disclosed in the aforementioned patent, the properties of one of the rare earth metal borides, namely lanthanum hexaboride, are particularly desirable for electron emitters. For this reason, lanthanum hexaboride has achieved an especially high status in the realm of thermionic emissive materials. Misch metal hexaboride is a highly desirable material when economy is important because misch metal, an alloy of the rare earth metals, is readily available and relatively inexpensive.
It is an object of this invention to provide a cathode having an improved support for metallic boride emitters.
It is another object of this invention to provide a cathode having an improved support for lanthaum hexaboride or misch metal hexaboride emitters.
Briefly, the cathode of the present invention includes a support having a surface region consisting of rhenium which is in contact with and carries the thermionic emissive material. Preferably, the support takes the form of a loosely wound coil of wire consisting essentially of rhenium. The coil is filled with a metallic boride emitter material, such as lanthanum hexaboride, which is sintered. It has been discovered in a cathode of this description that the boron atoms do not diffuse into the rhenium base material at elevated temperatures. No reaction between the rhenium and lanthanum boride was observed.
The invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.
In the drawings:
FIGURE 1 illustrates a cathode embodying the present invention;
FIGURE 2 is a cross-sectional view of the cathode of FIGURE 1;
FIGURE 3 is a cross-sectional View of an alternative cathode assembly embodying the present invention;
FIGURE 4is a cross-sectional view of another alternative cathode assembly embodying the present invention; and
FIGURE 5 is a cross-sectional view of yet another alternative cathode assembly embodying the present invention.
It has been found that when certain metal borides are in contact with commonly used refractory metals such as tungsten, molybdenum, platinum, niobium or tantalum at high temperatures, boron dilfuses into these metal lattices forming interstitial boron alloys which are very brittle. The metal of the boron compound is thereby released into the device and the supply of emissive material is reduced.
3,3 12,856 Patented Apr. 4, 1967 While the present invention pertains to supports for cathodes utilizing metal borides as emitters in general, the following description, for purposes of clarity and brevity, will be confined to cathodes utilizing lanthanum hexaboride as the emitter material since, as mentioned above, lanthanum hexaboride possesses particularly desirable properties which render this material one of the most commonly selected borides for thermionic electron emitters. These properties are clearly set forth in the above-mentioned Patent No. 2,639,399. It is to be understood that the present invention is not limited to cathodes utilizing lanthanum hexaboride and extends to other borides, for example, the economically desirable misch metal hexaboride.
As a result of an intensive search for an improved support for a cathode utilizing lanthanum hexaboride emissive material, we have discovered that rhenium possesses the sought-after physical and mechanical properties and can be utilized as the material for an elfective support which is impervious to boron atoms. Thus, the deleterious elfects of boron diffusion at high temperatures are avoided.
Rhenium is an element occurring in small amounts throughout the surface of the earth. In bulk form it resembles tungsten or rhodium and it is refractory metal having a melting point of 3100 C. Rhenium has a hexagonal crystal structure and its volatilization in vacuo is negligible at the operating temperature of the boride emitters. It can be worked mechanically and is available in the form of a bendable wire.
Byway of more clearly pointing out the particular features of the cathode of the present invention, it-should be noted that rhenium possesses thermionic emissive properties similar to those of tungsten. It is known that rhenium can be used as a thermionic emissive material, but, like tungsten, rhenium provides little electron emission at the usual temperature of operation of the more efiicient thermionic electron emissive materials. Lanthanum hexaboride, for example, provides a copious supply of electrons at temperatures in the order of 1400 C. At this temperature, the electron emission from rhenium is negligible by comparison. The rhenium support utilized in the cathode of this invention is used as a base material to support the lanthanum hexaboride and takes no part in the electron emission properties of the cathode.
In FIGURES 1 and 2 there is shown a cathode constructed in accordance with the present invention. The support comprises a coil 1 having a plurality of turns 2 of wire consisting essentially of rhenium. The thermionic emitter is a coating 3 of lanthanum hexaboride which fills coil 1 and is supported thereby.
A cathode such as shown in FIGURES 1 and 2 was constructed by winding a 0.020 diameter rhenium wire about a 0.020 diameter mandrel, which was thereafter removed. As shown, coil 1 is loosely wound, that is say, there is a spacing or gap between turns 2. In one specific example, the distance between turns was 0.020". Coating 3 may be applied by spraying, dipping or painting, but, a particularly effective method is to fill the voids inside and between turns 2 of coil 1 and thereafter sinter the lanthanum hexaboride to provide a complete encapsulation of coil 1. Reference may be had to the aforementioned Patent No. 2,639,399 for a more detailed description of methods which may be used to provide the desired coating 3 on coil 1.
Coil leads 4 and 5 provide means for supporting the cathode and means for supplying heating current thereto. In addition, one of leads 4 and 5 is utilized to provide electrical circuit connection to the cathode.
A cathode constructed as shown in FIGURES 1 and 2 and utilizing the above dimensions, which have been given by way of example, was used in an electron discharge device. The cathode operated for 1000 hours at 1400 C. without dimunition of the emissive properties of coating 3. Inspection thereafter under the microscope showed no diffusion or other reaction between the rhenium support and lanthanum boride emissive material.
FIGURE 3 shows an alternative embodiment of a cathode constructed in accordance with the present invention. The embodiment of FIGURE 3 provides a more rigid support than is normally obtainable by utilizing only coil leads, such as leads 4 and 5 in the embodiment of FIGURES 1 land 2.
The support of FIGURE 3 includes a pair of side members 6 and 7, which are normally rigidly fastened to an assembly variously known as the stem, header or base of the electron discharge device. Members 6 and 7 are illustrated as having support caps 8 and 9 secured, as by welding, at the upper extremities thereof, respectively. Caps 8 and 9 provide means for securing a relatively large diameter rhenium tube 10 at opposite ends thereof adjacent members 6 and 7. The cathode support is completed by a coil of relatively small diameter rhenium wire having a plurality of turns 11 wound about tube 10. The extremities of the coil are secured, as by welding, to tube 10 at points 13 and 14, but may be secured, alternatively, to members 6 and '7 or caps 8 and 9. The heater circuit connection to tube 10 is provided through members 6 and 7 and caps 8 and 9 which are constructed of conductive material. A coating 12 of lanthanum boride is disposed about tube 10 and between turns 11 by any of the usual methods, such as filling and sintering in place. It may be seen that all of the surface regions of the support of FIG- URE 3 which contact lanthanum hexaboride coating 12, namely tube 10 and the coil wound thereon, consist essentially of rhenium. Thus, diffusion of boron atoms into any part of the support is avoided.
In the cathode of FIGURE 4, a lanthanum boride coating 15 is disposed about and carried by rhenium support wire 17. In this embodiment, the heating coil, comprising turns 16, is not in contact with coating 15. Therefore, it is not necessary that the heating coil be constructed of rhenium wire, and the material may be any of the usual resistive refractory metals used for this purpose. Support members 6 and 7 and caps 8 and 9 should be conductive in this embodiment in order to provide electrical circuit connection to coating 15, since the heating coil is not connected to the support, as in the embodiment of FIG- URE 1.
FIGURE 5 illustrates a hairpin cathode constructed in accordance with the present invention. The cathode support comprises a pair of side members 18 and 19 carrying a rhenium wire 20. Wire 20 is in the general form. of an inverted V and secured, as by welding, to members 18 and 19, respectively, at extremities thereof. A rhenium wire 21 of lesser diameter is disposed about wire 20 in a plurality of turns 22, terminating in extremities 23 and 24 which are secured to wire 20, as by welding thereto. Alternatively, extremities 23 and 24 may be secured to members 18 and 19, respectively. In one particularly satisfactory support of this variety the diameter of wire 20 was double the diameter of wire 21 and the spacing between loosely wound turns 22 was equal to the diameter of wire 21.
As in the embodiment of FIGURE 3, side members 18 and 19 of FIGURE 5 are electrically conductive and serve as part of the cathode circuit and heater circuit. It is not required that wire 21 provide any appreciable electric circuit path since the heating current flows predominantly through wire 20. Wire 21 merely serves as a mechanical support for coating 25.
By way of example, a hairpin cathode of the type shown in FIGURE 5 was constructed wherein wire 20 was IO-miI-diameter rhenium wire and wire 21 was S-mildiameter rhenium wire with 5 mils betewen turns. Wire 21 was welded to wire 20 at opposite extremities of wire 20, adjacent members 18 and 19, respectively. The space between turns was filled with lanthanum hexaboride by painting with a paste of boride powder and amyl acetate. The cathode was sintered in argon for 5 minutes at 1600 C. The completed cathode supplied an emission current of 10' ampere at a surface temperature of only 675 C. The heating current supplied through members 18 and 19 was 1.8 amperes and heating power was 1.7 watts. No diffusion of boron into the rhenium support was observed when the cathode was later examined under a microscope.
While this invention has been described in connection with four specific cathode structures embodying the present invention, it is to be understood that the present invention is not limited thereto. Many variations and modifications of the specific cathodes disclosed will occur to those skilled in the art. In addition, other cathodes may be constructed utilizing a rhenium support for a metal boride thermionic emissive material. Therefore, it is intended by the following claims to include all such cathode structures as fall within thetrue spirit and scope of this invention.
What is claimed as new and desired to be secured by Letters Patent of the United States is:
1. A thermionic cathode comprising: a support, said support including a surface region consisting of rhenium; and a thermionic emissive material consisting of a metal boride, which does not diffuse into rhenium at elevated temperatures, in contact with said surface region and carried by said support.
2. A thermionic cathode comprising: a support, said support consisting essentially of rhenium; and a coating of thermionic material disposed on said support, said material consisting essentially of at least one metal boride selected from the group consisting of the borides of calcium, barium, strontium, thorium, uranium and the rare earth metals.
3. The thermionic cathode of claim 2 metal boride is lanthanum hexaboride.
4. The thermionic cathode of claim 2 wherein said metal boride is misch metal hexaboride.
5. A thermionic cathode comprising: a support, said support including a loosely wound coil of wire consisting of rhenium; and a coating of thermionic emissive material disposed about said coil and supported thereby, said ma terial consisting essentially of at least one metal hexaboride selected from the group consisting of the borides wherein said of calcium, barium, strontium, thorium, uranium and the rare earth metals.
6. The thermionic cathode of claim 5 wherein said metal hexaboride is lanthanum hexaboride.
7. The thermionic cathode of claim 5 wherein said metal hexaboride is misch metal hexaboride.
References Cited by the Examiner UNITED STATES PATENTS 1,777,253 9/1930 Bruijnes et al. 313-345 X 1,854,970 4/1932 Agte 313-311 2,098,113 11/1937 Spaeth 313-346 X 2,258,158 10/1941 Lowry 313-344 2,300,959 11/1942 Pirani 313-344 2,586,768 2/1952 Bash 313-346 2,639,399 5/1953 Lafferty 313-345 X 2,820,920 1/1958 Penon 313-345 X JOHN W. HUCKERT, Primary Examiner.
A. 1. JAMES, Assistant Examiner.
Claims (1)
1. A THERMIONIC CATHODE COMPRISING: A SUPPORT, SAID SUPPORT INCLUDING A SURFACE REGION CONSISTING OF REHENIUM; AND A THERMIONIC EMISSIVE MATERIAL CONSISTING OF A METAL BORIDE, WHICH DOES NOT DIFFUSE INTO RHENIUM AT ELEVATED TEMPERATURES, IN CONTACT WITH SAID SURFACE REGION AND CARRIED BY SAID SUPPORT.
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US268107A US3312856A (en) | 1963-03-26 | 1963-03-26 | Rhenium supported metallic boride cathode emitters |
DEG40191A DE1234858B (en) | 1963-03-26 | 1964-03-25 | Incandescent cathode for electric discharge tubes |
NL6403351A NL6403351A (en) | 1963-03-26 | 1964-03-26 | |
FR968759A FR1391306A (en) | 1963-03-26 | 1964-03-26 | Cathode for electronic discharge device |
GB12980/64A GB1041282A (en) | 1963-03-26 | 1964-03-26 | Cathode for electron discharge device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US268107A US3312856A (en) | 1963-03-26 | 1963-03-26 | Rhenium supported metallic boride cathode emitters |
Publications (1)
Publication Number | Publication Date |
---|---|
US3312856A true US3312856A (en) | 1967-04-04 |
Family
ID=23021505
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US268107A Expired - Lifetime US3312856A (en) | 1963-03-26 | 1963-03-26 | Rhenium supported metallic boride cathode emitters |
Country Status (4)
Country | Link |
---|---|
US (1) | US3312856A (en) |
DE (1) | DE1234858B (en) |
GB (1) | GB1041282A (en) |
NL (1) | NL6403351A (en) |
Cited By (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3427491A (en) * | 1966-04-20 | 1969-02-11 | Matsushita Electronics Corp | Discharge tube |
US3427492A (en) * | 1966-04-20 | 1969-02-11 | Matsushita Electronics Corp | Discharge tube satisfactorily low in radio-interfering noise |
US3436584A (en) * | 1966-03-15 | 1969-04-01 | Gen Electric | Electron emission source with sharply defined emitting area |
US3440475A (en) * | 1967-04-11 | 1969-04-22 | Lokomotivbau Elektrotech | Lanthanum hexaboride cathode system for an electron beam generator |
US3462635A (en) * | 1966-10-24 | 1969-08-19 | Ibm | Holder for highly reactive cathodes of rare-earth borides such as lanthanum hexaboride,the holder provided with a cooling means opposite to the emissive end of the cathode in order to reduce tendency of holder deterioration |
US3500106A (en) * | 1965-09-10 | 1970-03-10 | Bell & Howell Co | Cathode |
US3513349A (en) * | 1966-01-08 | 1970-05-19 | Matsushita Electronics Corp | Discharge tube |
US3558966A (en) * | 1967-03-01 | 1971-01-26 | Semicon Associates Inc | Directly heated dispenser cathode |
US3631291A (en) * | 1969-04-30 | 1971-12-28 | Gen Electric | Field emission cathode with metallic boride coating |
US3668457A (en) * | 1969-08-25 | 1972-06-06 | United Aircraft Corp | Brazing alloy for bonding thermionic cathode to support |
US3728570A (en) * | 1968-07-07 | 1973-04-17 | Department Of Eng University O | Electron probe forming system |
US3758808A (en) * | 1970-07-30 | 1973-09-11 | Licentia Gmbh | Dispenser cathode and method for making same |
JPS4953660U (en) * | 1972-08-22 | 1974-05-11 | ||
US3833494A (en) * | 1972-05-30 | 1974-09-03 | Philips Corp | Method of manufacturing a lanthanum hexaboride-activated cathode for an electric discharge tube |
US3932314A (en) * | 1973-09-05 | 1976-01-13 | Hitachi, Ltd. | Hexaboride electron emissive material |
JPS5128475A (en) * | 1974-09-04 | 1976-03-10 | Hitachi Ltd | MAGUNETORONINKYOKUKOTAI |
US3944866A (en) * | 1974-04-08 | 1976-03-16 | Canadian Patents & Development Ltd. | Thermionic emitter of lanthanum strontium vanadates |
JPS5132268A (en) * | 1974-09-13 | 1976-03-18 | Hitachi Ltd | |
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 |
US4137476A (en) * | 1977-05-18 | 1979-01-30 | Denki Kagaku Kogyo Kabushiki Kaisha | Thermionic cathode |
US4258283A (en) * | 1978-08-31 | 1981-03-24 | Balzers Aktiengesellschaft Fur Hochvakuumtechnik Und Dunne Schichten | Cathode for electron emission |
EP0013201B1 (en) * | 1978-12-27 | 1982-05-19 | Thomson-Csf | Directly heated cathode and high frequency electron tube comprising such a cathode |
US4482839A (en) * | 1981-05-29 | 1984-11-13 | Denki Kagaku Kogyo Kabushiki Kaisha | Thermionic emission cathode and preparation thereof |
US4760306A (en) * | 1983-06-10 | 1988-07-26 | The United States Of America As Represented By The United States Department Of Energy | Electron emitting filaments for electron discharge devices |
EP1983547A1 (en) | 2007-04-20 | 2008-10-22 | PANalytical B.V. | X-ray source |
US20100301736A1 (en) * | 2007-11-30 | 2010-12-02 | Toshiyuki Morishita | Electron emitting source and manufacturing method of electron emitting source |
US8878422B2 (en) | 2010-10-25 | 2014-11-04 | Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. | Device for producing an electron beam |
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US1777253A (en) * | 1926-04-06 | 1930-09-30 | Philips Nv | Oxide cathode |
US1854970A (en) * | 1930-05-20 | 1932-04-19 | Gen Electric | Electric lamp and the illuminating body used therein |
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US2586768A (en) * | 1949-02-24 | 1952-02-26 | Driver Harris Co | Vacuum tube electrode element |
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US2820920A (en) * | 1952-09-17 | 1958-01-21 | Claude Ets | Manufacture of coated electrodes |
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DE883935C (en) * | 1938-12-02 | 1953-07-23 | Lorenz C Ag | Cathode for electron tubes |
US2659685A (en) * | 1950-03-31 | 1953-11-17 | Gen Electric | Boride cathodes |
-
1963
- 1963-03-26 US US268107A patent/US3312856A/en not_active Expired - Lifetime
-
1964
- 1964-03-25 DE DEG40191A patent/DE1234858B/en active Pending
- 1964-03-26 GB GB12980/64A patent/GB1041282A/en not_active Expired
- 1964-03-26 NL NL6403351A patent/NL6403351A/xx unknown
Patent Citations (8)
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US1777253A (en) * | 1926-04-06 | 1930-09-30 | Philips Nv | Oxide cathode |
US1854970A (en) * | 1930-05-20 | 1932-04-19 | Gen Electric | Electric lamp and the illuminating body used therein |
US2098113A (en) * | 1932-02-06 | 1937-11-02 | Spaeth Charles | Lamp and method of operating same |
US2300959A (en) * | 1940-01-01 | 1942-11-03 | Gen Electric | Cathode for discharge devices |
US2258158A (en) * | 1940-11-23 | 1941-10-07 | Hygrade Sylvania Corp | Electric discharge lamp cathode |
US2586768A (en) * | 1949-02-24 | 1952-02-26 | Driver Harris Co | Vacuum tube electrode element |
US2639399A (en) * | 1950-03-31 | 1953-05-19 | Gen Electric | Electron emitter |
US2820920A (en) * | 1952-09-17 | 1958-01-21 | Claude Ets | Manufacture of coated electrodes |
Cited By (37)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3500106A (en) * | 1965-09-10 | 1970-03-10 | Bell & Howell Co | Cathode |
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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 |
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 |
US4137476A (en) * | 1977-05-18 | 1979-01-30 | Denki Kagaku Kogyo Kabushiki Kaisha | Thermionic cathode |
US4258283A (en) * | 1978-08-31 | 1981-03-24 | Balzers Aktiengesellschaft Fur Hochvakuumtechnik Und Dunne Schichten | Cathode for electron emission |
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US4482839A (en) * | 1981-05-29 | 1984-11-13 | Denki Kagaku Kogyo Kabushiki Kaisha | Thermionic emission cathode and preparation thereof |
US4760306A (en) * | 1983-06-10 | 1988-07-26 | The United States Of America As Represented By The United States Department Of Energy | Electron emitting filaments for electron discharge devices |
US20100150315A1 (en) * | 2007-04-20 | 2010-06-17 | Bart Filmer | X-ray source |
EP1983546A1 (en) * | 2007-04-20 | 2008-10-22 | PANalytical B.V. | X-ray cathode and tube |
WO2008129006A1 (en) * | 2007-04-20 | 2008-10-30 | Panalytical B.V. | X-ray source |
EP1983547A1 (en) | 2007-04-20 | 2008-10-22 | PANalytical B.V. | X-ray source |
JP2010525506A (en) * | 2007-04-20 | 2010-07-22 | パナリティカル ビー ヴィ | X-ray source |
CN101720491B (en) * | 2007-04-20 | 2012-07-04 | 帕纳科有限公司 | X-ray source |
US8223923B2 (en) | 2007-04-20 | 2012-07-17 | Panaltyical B.V. | X-ray source with metal wire cathode |
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 |
US8878422B2 (en) | 2010-10-25 | 2014-11-04 | Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. | Device for producing an electron beam |
RU2557078C2 (en) * | 2010-10-25 | 2015-07-20 | Фраунхофер-Гезелльшафт Цур Фердерунг Дер Ангевандтен Форшунг Е.Ф. | Electronic beam generator |
Also Published As
Publication number | Publication date |
---|---|
DE1234858B (en) | 1967-02-23 |
GB1041282A (en) | 1966-09-01 |
NL6403351A (en) | 1964-09-28 |
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