US1967869A - X-ray device - Google Patents

X-ray device Download PDF

Info

Publication number
US1967869A
US1967869A US484067A US48406730A US1967869A US 1967869 A US1967869 A US 1967869A US 484067 A US484067 A US 484067A US 48406730 A US48406730 A US 48406730A US 1967869 A US1967869 A US 1967869A
Authority
US
United States
Prior art keywords
target
chute
envelope
ray device
conducting
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
Application number
US484067A
Inventor
William D Coolidge
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.)
General Electric Co
Original Assignee
General Electric Co
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
Priority to US14297326A priority Critical
Priority to US244014A priority patent/US1936424A/en
Application filed by General Electric Co filed Critical General Electric Co
Priority to US484067A priority patent/US1967869A/en
Priority claimed from FR40809D external-priority patent/FR40809E/en
Application granted granted Critical
Publication of US1967869A publication Critical patent/US1967869A/en
Anticipated expiration legal-status Critical
Application status is Expired - Lifetime legal-status Critical

Links

Images

Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00X-ray tubes

Description

July 24; 1934. w CQOLIDGE 1,967,869

X-RAY DEVICE Filed Sept. 24, 1930 Inventor; Willicrm D. Coo iidge,

I bg

His Atbor 'neg.

l normal operation of the device.

i'i '1 into the bulb 2.

Patented July 24, 1934 X-RAY DEVICE William D. Coolidge, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application September 24, 1930, Serial No. 484,067

2 Claims.

The present invention comprises an improved X-ray device which is particularly suitable for the generation of X-rays of high penetrability.

This application constitutes a continuation-in- 5 part of my prior application Serial No. 244,014,

filed December 31, 1927.

When X-rays are generated by the impact of high speed electrons on a target, secondary electrons are emitted as well as X-rays. These secll) ondary electrons are projected upon the back of the target, or anode, the anode stem, and the surrounding glass parts. In devices of moderate current value, or operating voltage, these sec ondary electrons do not seriously interfere with At very high operating voltages, and particularly at substantial current values, the secondary electrons by charging the envelope near the anode to high negative potentials, set up such high electric '20 strains as to cause puncture of the envelope.

In accordance with my invention, these difficulties are overcome by providing the target (commonly the target forms part of the anode) with a closely surrounding tubular extension, or

' chute, which extends toward the cathode and acts as a shield for intercepting secondary electrons. This shield should be long relative to its diameter so that the solid angle subtended by its mouth from the target face is relatively small.

' Preferably the target shielding tube in my improved device has a length more than twice its diameter.

In the accompanying drawing Fig. 1 is a side elevation of a device embodying my invention with a diagram of electrical connections; Fig. 2

is an enlarged sectional view of the target end of the device shown in Fig. 1, and Fig. 3 is a sectional view of a modification.

The X-ray device shown in Fig. 1 comprises a sectional container constituted of two bulbous glass chambers 1, 2, joined at their necks 3, 4, by a metallic coupling member 5 which is iusionsealed to the necks of the glass bulbs. A metal chute consisting of a section 6 of small diameter and a section 7 of greater diameter extends through the coupling 5. A thermionic cathode (not shown) within a focusing device 8 in the bulb 1, projects a beam of electrons into the chute 6 through the coupling 5 and through the chute The enlarged diameter of the second chute 7 is required to accommodate the enlargement of the electron beam due to the distribution of the electric field. From the chute '7 the electron beam passes into a metal chute 9 having a diameter substantially equal to the diameter of the chute 7. In the chute 9 is located 5 a target 10 (see Figs. 2 and 3). The open ends of the chutes are provided with enlarged edges to equalize the field, thereby avoiding cold cathode efiect. 0

Before the structural details of the target and connected parts are described, attention is di rected to the electrical connections whereby electric fields are established for giving the electrons successive accelerations. Between the cathode with its independent heating circuit 11, and the coupling 5 and from thence to chute 6 is connected the secondary of a transformer 12. Between the coupling 5 and chute 7 and the anode terminal 13 is connected the secondary of a trans- 7 former 14. The connection between the coupling 5 and the common terminal of the secondaries of the transformers 12, 14, is made preferably by grounds 15, 16, as indicated. The primary windings of the transformers 12, 14, are connected in .75 parallel to the supply mains 17.

As shown in Fig. 2, a metal reservoir 20 for containing a cooling fluid is mounted on a metal tube 21 which is sealed by fusion to the neck 22 of the glass envelope 2. The chute 9 communicates with this reservoir which is mounted thereon by a ring 23 to which it is fastened by suitable screws 24, a suitable gasket being provided.

A wall 10 constituting the target and consisting of copper plate 25 is faced with a plate 26 of tungsten, or other suitable refractory metal. In the form of device shown in Fig. 2, the target 10 is located short of the end of the chute 9 so that X-rays may be conveniently utilized when passing through a window 27 in the chute 9 as pictorially indicated. This window preferably is covered with a sheet 28 of thin metal, for example aluminum.

In the embodiment shown in Fig. 3, the target 10 closes the end of the chute 9, and the reservoir 20 is omitted. The sheet of tungsten 26 should be thin enough to permit of the effective passage of X-rays through it. In this form of device, theb acking plate 25 of copper may be artificially cooled by circulation of a cooling fluid, as indi- 3100 The part 515 of chute or tube 9 extending from the target 10 toward its mouth is about fourteen inches in length. In the modification shown by Fig. 3, the chute 9 is somewhat longer. An inconsiderable part of the secondary electrons emitted at the target escape from the mouth of the chute 9. Such a device is operable at voltages as high as about five hundred thousand volts with currents of an amperage of the order of three milliarnperes without deleterious effects due to secondary emission at the target.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An X-ray tube comprising an envelope constituted of conducting and non-conducting sections joined together, a cathode and a target in said envelope, means for preventing secondary electrons generated at the target from striking the envelope, said means including a metal shield carried by one of the conducting envelope sections, said shield closely surrounding the target and connected thereto and being interposed between the target and the non-conducting envelope section in the region of the target.

2. An X-ray tube comprising an envelope constituted of conducting and non-conducting sections joined together, a cathode and a target in said envelope, means for preventing secondary electrons generated at the target from striking the envelope, said means including a hollow metal shield carried by one of the conducting envelope sections and containing said target, said shield connected to said target and extending over a substantial portion of the non-conducting envelope section in the region of the target and being interposed between said non-conducting envelope section and the target.

WILLIAM D. COOLIDGE.

US484067A 1926-10-20 1930-09-24 X-ray device Expired - Lifetime US1967869A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US14297326A true 1926-10-20 1926-10-20
US244014A US1936424A (en) 1926-10-20 1927-12-31 Electrical discharge device and method of operation
US484067A US1967869A (en) 1926-10-20 1930-09-24 X-ray device

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US484067A US1967869A (en) 1926-10-20 1930-09-24 X-ray device
FR40809D FR40809E (en) 1926-10-20 1931-09-23 Improvements in electronic discharge tubes and the means to prevent these tubes in the production of harmful ionization
GB2668631A GB383356A (en) 1926-10-20 1931-09-24 Improvements in and relating to x-ray devices

Publications (1)

Publication Number Publication Date
US1967869A true US1967869A (en) 1934-07-24

Family

ID=27385878

Family Applications (1)

Application Number Title Priority Date Filing Date
US484067A Expired - Lifetime US1967869A (en) 1926-10-20 1930-09-24 X-ray device

Country Status (1)

Country Link
US (1) US1967869A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2535708A (en) * 1948-04-10 1950-12-26 Gen Electric X Ray Corp X-ray generator
US2735018A (en) * 1956-02-14 Mclachlan
US2816241A (en) * 1951-09-27 1957-12-10 Gen Electric Electron targets and means for and method of cooling the same
US2903611A (en) * 1955-05-06 1959-09-08 Vickers Electrical Co Ltd X-ray tube comprising a cast copper anode sealed with a copper-silver electric alloy
US4034251A (en) * 1976-02-23 1977-07-05 North American Philips Corporation Transmission x-ray tube
US20080310595A1 (en) * 2007-05-16 2008-12-18 Passport Systems, Inc. Thin walled tube radiator for bremsstrahlung at high electron beam intensities

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2735018A (en) * 1956-02-14 Mclachlan
US2535708A (en) * 1948-04-10 1950-12-26 Gen Electric X Ray Corp X-ray generator
US2816241A (en) * 1951-09-27 1957-12-10 Gen Electric Electron targets and means for and method of cooling the same
US2903611A (en) * 1955-05-06 1959-09-08 Vickers Electrical Co Ltd X-ray tube comprising a cast copper anode sealed with a copper-silver electric alloy
US4034251A (en) * 1976-02-23 1977-07-05 North American Philips Corporation Transmission x-ray tube
US20080310595A1 (en) * 2007-05-16 2008-12-18 Passport Systems, Inc. Thin walled tube radiator for bremsstrahlung at high electron beam intensities
US7983396B2 (en) * 2007-05-16 2011-07-19 Passport Systems, Inc. Thin walled tube radiator for bremsstrahlung at high electron beam intensities
US20110255669A1 (en) * 2007-05-16 2011-10-20 Passport Systems, Inc. Thin walled tube radiator for bremsstrahlung at high electron beam intensities
US8340251B2 (en) * 2007-05-16 2012-12-25 Passport Systems, Inc. Thin walled tube radiator for bremsstrahlung at high electron beam intensities

Similar Documents

Publication Publication Date Title
US3691417A (en) X-ray generating assembly and system
EP2179436B1 (en) Compact high voltage x-ray source system and method for x-ray inspection applications
US2980819A (en) Thermal energy converter
US2367332A (en) Cathode
US2952790A (en) X-ray tubes
US3916202A (en) Lens-grid system for electron tubes
US3679927A (en) High power x-ray tube
GB545689A (en) Improvements relating to the construction and arrangement of electrodes in electron discharge devices
US2291948A (en) High voltage X-ray tube shield
US2569872A (en) Electron discharge tube
GB317451A (en) Improvements in x-ray tubes
US1907507A (en) Electron discharge device
US2951960A (en) Gaseous discharge device
US1917099A (en) x-ray tube
GB376761A (en) Improvements in or relating to electric vacuum tubes
US3751701A (en) Convergent flow hollow beam x-ray gun with high average power
US2559526A (en) Anode target for high-voltage highvacuum uniform-field acceleration tube
US2400456A (en) Spark gap electrical apparatus
CN103733734B (en) Radiation generator and radiation imaging apparatus
US1203495A (en) Vacuum-tube.
US3138729A (en) Ultra-soft X-ray source
US1946288A (en) Electron discharge device
US2228157A (en) Construction of gas-or vapor-filled discharge vessels
US1211092A (en) X-ray tube.
US2517260A (en) Apparatus for generating an accurately focused beam of charged particles and for related purposes