GB240166A - Improvements in and relating to electron discharge devices - Google Patents

Improvements in and relating to electron discharge devices

Info

Publication number
GB240166A
GB240166A GB23210/25A GB2321025A GB240166A GB 240166 A GB240166 A GB 240166A GB 23210/25 A GB23210/25 A GB 23210/25A GB 2321025 A GB2321025 A GB 2321025A GB 240166 A GB240166 A GB 240166A
Authority
GB
United Kingdom
Prior art keywords
cathode
shield
uranium
parts
rod
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
Application number
GB23210/25A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
British Thomson Houston Co Ltd
Original Assignee
British Thomson Houston Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by British Thomson Houston Co Ltd filed Critical British Thomson Houston Co Ltd
Publication of GB240166A publication Critical patent/GB240166A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/06—Cathodes
    • H01J35/064—Details of the emitter, e.g. material or structure

Landscapes

  • X-Ray Techniques (AREA)
  • Microwave Tubes (AREA)

Abstract

240,166. British Thomson-Houston Co., Ltd., (Assignees of Coolidge, W. D.). Sept. 17, 1924, [Convention date]. R÷ntgen-ray tubes; vacuum tubes. - In a tube having a tungsten cathode and a member such as an anode consisting of a metal, for instance uranium or thorium, having a higher electron emissivity than tungsten, an electrostatic device is so arranged about the cathode that an increase of space current due to an increased emission from volatilizable metal deposited on the cathode is suppressed. As shown, a spiral cathode 13 is mounted in a cylindrical focusing shield 14 of molybdenum, and the ends of the cathode areconnected to the shield and to a central rod 15 at points removed from the mouth of the shield. The main part of the cathode is located near themouth of the shield and is heated to a temperature of 2500‹ F. which is sufficiently high to prevent deposition of uranium. The cooler partsof the cathode on which a deposit of uranium may take place are subjected to a strong electrostatic field and the consequent increased emission is thereby controlled so as to have no effect on the space current. The rod 15 projects beyond the spiral so as to broaden the focus. A flange 18 on the shield protects the parts behind the cathode from ionic bombardment during exhaustion. Uranium and thorium may act as a gas absorbent. In a modification the ends of the cathode are connected to parts nearer to themouth of the shield than as shown, and theelectrostatic field at those parts is increased by forming the shield with an inturned flange and the rod with a disc-shaped flange. In a furtherarrangement the whole of the cathode is mounted at a distance from the mouth of the shield. The anticathode may consist of a target of uranium. brazed to a copper backing by an alloy consisting of 28 parts of copper and 72 parts of silver, a cooling tube being brazed behind the backing. Specification 109,358 is referred to.
GB23210/25A 1924-09-17 1925-09-17 Improvements in and relating to electron discharge devices Expired GB240166A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US738246A US1684263A (en) 1924-09-17 1924-09-17 Hot-cathode device

Publications (1)

Publication Number Publication Date
GB240166A true GB240166A (en) 1926-03-11

Family

ID=24967198

Family Applications (1)

Application Number Title Priority Date Filing Date
GB23210/25A Expired GB240166A (en) 1924-09-17 1925-09-17 Improvements in and relating to electron discharge devices

Country Status (4)

Country Link
US (1) US1684263A (en)
DE (1) DE483337C (en)
FR (1) FR603584A (en)
GB (1) GB240166A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003065772A2 (en) * 2002-01-31 2003-08-07 The Johns Hopkins University X-ray source and method for producing selectable x-ray wavelength

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3526799A (en) * 1967-05-26 1970-09-01 Gen Electric Electron discharge device subject to hydrocarbon background pressure and having carbon-dissolving electrodes
DE2855905A1 (en) * 1978-12-23 1980-06-26 Licentia Gmbh DEVICE WITH A X-RAY TUBE
NL8603264A (en) * 1986-12-23 1988-07-18 Philips Nv ROENTGEN TUBE WITH A RING-SHAPED FOCUS.
US9240303B2 (en) * 2013-09-10 2016-01-19 Moxtek, Inc. Dual tube support for electron emitter

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003065772A2 (en) * 2002-01-31 2003-08-07 The Johns Hopkins University X-ray source and method for producing selectable x-ray wavelength
WO2003065772A3 (en) * 2002-01-31 2004-02-26 Univ Johns Hopkins X-ray source and method for producing selectable x-ray wavelength
US7186022B2 (en) 2002-01-31 2007-03-06 The Johns Hopkins University X-ray source and method for more efficiently producing selectable x-ray frequencies

Also Published As

Publication number Publication date
US1684263A (en) 1928-09-11
FR603584A (en) 1926-04-19
DE483337C (en) 1929-09-30

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