US1942007A - Soft x-ray tube - Google Patents

Soft x-ray tube Download PDF

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Publication number
US1942007A
US1942007A US419479A US41947930A US1942007A US 1942007 A US1942007 A US 1942007A US 419479 A US419479 A US 419479A US 41947930 A US41947930 A US 41947930A US 1942007 A US1942007 A US 1942007A
Authority
US
United States
Prior art keywords
window
tube
rays
soft
envelope
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
US419479A
Other languages
English (en)
Inventor
Charles M Slack
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.)
Westinghouse Lamp Co
Original Assignee
Westinghouse Lamp 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
Application filed by Westinghouse Lamp Co filed Critical Westinghouse Lamp Co
Priority to US419479A priority Critical patent/US1942007A/en
Priority to FR708594D priority patent/FR708594A/fr
Priority to GB826/31A priority patent/GB361179A/en
Application granted granted Critical
Publication of US1942007A publication Critical patent/US1942007A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/32—Tubes wherein the X-rays are produced at or near the end of the tube or a part thereof which tube or part has a small cross-section to facilitate introduction into a small hole or cavity
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/16—Vessels; Containers; Shields associated therewith
    • H01J35/18—Windows

Definitions

  • the present invention relates to devices employed in the production of X-rays of long wave length, usually termed soft X-rays or Grenz rays, and particularly to the production of X- 5 rays of from 2 to 8 angstroms in wave length.
  • Aluminium foil of a thinness of 0.004 m. m. or about 0.00015 inches such as employed by Weh- ...nelt and Trenkle is extremely fragile and if of 40 any appreciable area, it must be supported by a.
  • Lindemann glass windows present the disadvantage that due to the brittleness of this material a window capable of withstanding atmospheric pressure is limited in thickness to a minimum of about 0.008 inches at which thickness a major portion of the rays of 3 angstrom wave length are absorbed by the window. From a manufacturing standpoint Lindemann glass presents a further disadvantage in that it is difficult to effect a good seal between a thin film of this material and the ordinary glass portions of a tube.
  • Lindemann glass Another disadvantage of Lindemann glass is that it deteriorates on exposure to atmosphere and must be coated with some such material as shellac or lacquer to protect it This coating must be renewed frequently or the rays themselves disintegrate the coating material.
  • One of the objectsof my invention is to provide an improved window for a soft X-ray tube which will project a major portion of the X-rays produced through the same.
  • Another object of my invention is to overcome the difficulties inherent in the windows in use at the present time and to employ a portion of the glass envelope of the device through which soft X-rays may be projected.
  • a still further object is to produce a window 7 for a soft X-ray tube which may be made extremely thin while retaining suflicient strength to resist the external atmospheric pressure and which will absorb but a very small proportion of the soft X-raysproduced in the tube.
  • my invention provide a window permeable to soft X-rays and composed of glass or other vitreous material of extreme thinness such as the one described in my Patent 1" 1,735,302 issued November 12, 1929. 5
  • this window consists in an indrawn bulbous portionon the end of the tube of a thickness of from 0.0001 to .005 inches.
  • the thickness should be less than 2 mils since with a wave length of 2 angstroms, the most penetrating of those considered, a window 10 mils thick will transmit less than one part in a thousand of the radiations, a window 5 mils thick will transmit less than one percent, a 2 mil window will transmit 14 percent, a 1 mil window 40 percent, and a 0.1 mil window will transmit'about 90 percent.
  • Fig. 1 is a central sectional view of a soft X- ray tube constructed in accordance with my invention.
  • FIGs. 2 and 3 are similar views on an enlarged scale disclosing other embodiments of my invention.
  • the tube shown in Fig. 1 comprises a glass envelope 1 having a relatively heavy wall and containing a filamentary cathode 2 and an anode 3.
  • the anode supporting end 4 of the tube has a reentrant glass stem 5 terminating in a press 6 through which a leading in conductor 7 for the anode is sealed.
  • the envelope 1 may be composed of any suit able glass, such as ordinary lime glass, pyrex or a glass which is less opaque to X-rays.
  • the cathode 2 may be of any suitable electron emitting material, but I prefer to construct it of tungsten or tantalum in the form of coil 8 mounted within a focusing cup 9 as is usual in X-ray tube construction.
  • the focusing cup 9 is supported by leading-in and supporting oonduo: tors 10 which are sealed in the press 12 of an outwardly projecting stem 11 located at the side of the tube adjacent the end 13 which is opposite the anode supporting end 4.
  • the end 13 of the tube may be e lar ed and the Window 14 formed therein.
  • window 14 the enlarged end is heated by a blow pipe flame or other suitable heating means and a suction created on the interior thereof so that the plastic glass is drawn in, the heating and suction being continued until the requisite size and thickness of the bulbous portion of the tube is obtained.
  • the Window 14 may preferably have a thickness of from 0.000104 to 0.002 inches.
  • the leading in and supporting conductors l0- may be ofiset as shown at 15 so as to dispose the. cathode 2 in close. proximity to "the. window 14 and at the same time. incline the focusing cup 9 away from the window so that cathode rays emerging from the filament 8 cannot strike the window, the filament being withdrawn into the focusing cup 9 to, eflfiect this result.
  • the foc u sing cup 9 directs cathode rays to. the centerof a target 16; of tungsten or thorium or other suitable material secured to the anode 3 thru efi rad at r 1 Water. 0.0 m devic may. h added in mann r wel ne rstqod inthe art.
  • a large area the window '14, is made shall w.- and i de mou h.- e. elec rqd s a also d s: posed closely adjacent the windowso. that the e ay mitted b he. tube orm. a l rg solid angle.
  • a soft X-ray tube embodying my invention embodying my invention and particularly designated for treatment of the mouth and throat.
  • This embodiment comprises a glass envelope 20 ofcylindrical shape and containsa cylindricar glass tube 21 supported at one end. in the envelope 20 by a sleeve 22. o 75 The free end of tube 21 supports on itsexwindow may be drawn very thin and have a.
  • a bonding d-is'c 137 which may- Leading-in conductors 28 for the coil 27 pass through apertures 29 in the end wall of shield 23 and emerge from the envelope 20 at about the central'portion thereof to join suitable terminals 30.
  • An anode 31 is centrally supported within the tube 21 by a sleeve 32 and a leading-in conductor 33 for the anode 31 is sealed in the press 35 of a, reentrant stem 34 in the same manner as previously described relative to elements 5, 6, '7 of Fig. 1.
  • a thin window 36 similar 1 is formed in the end of the envelope 20 opposite the anode supporting end and in alignment with the aperture 24, a filament coil 27 and anode 31.
  • the terminals 3Q are disposed remote from; said window to permit insertion of the window 36 and the portion of the envelope supporting the window into the mouth.
  • Fig. 3 another embodiment of my invention designed particularly for treatment of small areas such as those within the nose or ear is illustrated.
  • This tube may be constructed in essentially the same manner as the tube shown in Fig. 2 except for the window structure which comprises a'sniall thin window 36" formed in a 1 10 tube 3'7 of about a half inch or less in diameter.
  • the window 36 isformed on a piece of glass tube 37 and the tube, subsequently fused; to an envelope 20-.
  • the electrodes should be thoroughly degasilied in accordance with the practice followed in the construction 01' X--ray tubes.
  • the metal parts Prior to assembly the metal parts are heated to a red heat to remove the major portion of the occluded gases and. after assem- 129 bly the electrodes and associated parts are sealed into the envelope, a high vacuum created and the final degasification efifected' by electronic bombardment and high frequency induction heat-.
  • the tube may be sealed off from the pumps and constant. operating conditions ma be obtained when the tube isworkedat the potential necessary for the production of soft X-rays. If desired, a small pres,-. sure of from 1 to 10 microns of a monatimic gas. such as neon may be admitted to the envelope. In cit-her case the arrangement of the electrodes and gas pressures employed are such, that the device may be operated to produce X-rays in the absence of detrimental gaseous ionization. T
  • a potential difierence of 6 kilovolts may be impressed on the anode and cathode and by using a window of 0.00004 inches thickness about ninety percent of these radiations produced will pass through the window. If radiations of a minimum wave length of 8 angstroms are desired about 1.5 kilovolts potential difference is impressed on the electrodes. With the same window a lower percentage of the rays will be emitted by the tube.
  • my tube is particularly designed for the production of X-rays of from 2 to 8 angstroms, it is capable of transmitting radiations of a greater wave length, such as those from 8 to 15 angstroms.
  • An X-ray tube comprising an envelope of cylindrical form, a cathode and an anode within said envelope, leading-in conductors for said anode and cathode, the leading-in conductor for said anode extending through one end of the envelope and the leading-in conductors for said cathode extending from the sides of the envelope at diametrically opposed points, said envelope comprising a body portion containing an element whose atomic weight is greater than 16 and a window at the end of said envelope and of substantially the same composition as said body portion, said window being homogeneously united to said body portion and having a portion thereof of not greater than 0.002 inches in thickness, said leading-in conductors emerging from the envelope at points remote from the window.

Landscapes

  • Vessels And Coating Films For Discharge Lamps (AREA)
  • X-Ray Techniques (AREA)
US419479A 1930-01-09 1930-01-09 Soft x-ray tube Expired - Lifetime US1942007A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US419479A US1942007A (en) 1930-01-09 1930-01-09 Soft x-ray tube
FR708594D FR708594A (fr) 1930-01-09 1930-12-30 Perfectionnements aux tubes à rayons x
GB826/31A GB361179A (en) 1930-01-09 1931-01-09 Improvements in or relating to x-ray tubes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US419479A US1942007A (en) 1930-01-09 1930-01-09 Soft x-ray tube

Publications (1)

Publication Number Publication Date
US1942007A true US1942007A (en) 1934-01-02

Family

ID=23662450

Family Applications (1)

Application Number Title Priority Date Filing Date
US419479A Expired - Lifetime US1942007A (en) 1930-01-09 1930-01-09 Soft x-ray tube

Country Status (3)

Country Link
US (1) US1942007A (fr)
FR (1) FR708594A (fr)
GB (1) GB361179A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2725483A (en) * 1950-05-20 1955-11-29 Westinghouse Electric Corp Inspection of electron phosphor screens
US2866114A (en) * 1953-06-12 1958-12-23 Philips Corp Beryllium window x-ray tube
WO2007043391A1 (fr) 2005-10-07 2007-04-19 Hamamatsu Photonics K.K. Tube a rayons x et source de rayons x le comprenant
US20100314999A1 (en) * 2009-06-16 2010-12-16 Wellypower Optronics Corporation Lamp device

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3124710A (en) * 1960-03-17 1964-03-10 X-ray tubes
CA2464712A1 (fr) 2002-01-31 2003-08-07 The Johns Hopkins University Source de rayons x et procede pour la production plus efficace de frequences de rayons x au choix

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2725483A (en) * 1950-05-20 1955-11-29 Westinghouse Electric Corp Inspection of electron phosphor screens
US2866114A (en) * 1953-06-12 1958-12-23 Philips Corp Beryllium window x-ray tube
WO2007043391A1 (fr) 2005-10-07 2007-04-19 Hamamatsu Photonics K.K. Tube a rayons x et source de rayons x le comprenant
EP1933359A4 (fr) * 2005-10-07 2012-05-30 Hamamatsu Photonics Kk Tube a rayons x et source de rayons x le comprenant
US20100314999A1 (en) * 2009-06-16 2010-12-16 Wellypower Optronics Corporation Lamp device

Also Published As

Publication number Publication date
GB361179A (en) 1931-11-19
FR708594A (fr) 1931-07-25

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