US3916202A - Lens-grid system for electron tubes - Google Patents

Lens-grid system for electron tubes Download PDF

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Publication number
US3916202A
US3916202A US466728A US46672874A US3916202A US 3916202 A US3916202 A US 3916202A US 466728 A US466728 A US 466728A US 46672874 A US46672874 A US 46672874A US 3916202 A US3916202 A US 3916202A
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electrode
electrode means
anode
equipotential
electrons
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US466728A
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English (en)
Inventor
Robert F Heiting
Jr Edward T Rate
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General Electric Co
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General Electric Co
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Priority to US466728A priority Critical patent/US3916202A/en
Priority to CA224,695A priority patent/CA1034181A/en
Priority to DE2518688A priority patent/DE2518688C2/de
Priority to FR7513522A priority patent/FR2286499A1/fr
Priority to ES437333A priority patent/ES437333A1/es
Priority to IT22870/75A priority patent/IT1037741B/it
Priority to CH564475A priority patent/CH614313A5/xx
Priority to BE156016A priority patent/BE828673A/xx
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/26—Measuring, controlling or protecting
    • H05G1/30—Controlling
    • H05G1/52—Target size or shape; Direction of electron beam, e.g. in tubes with one anode and more than one cathode
    • 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
    • H01J35/045—Electrodes for controlling the current of the cathode ray, e.g. control grids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/14—Arrangements for concentrating, focusing, or directing the cathode ray
    • H01J35/147—Spot size control

Definitions

  • An electron tube such as an x-ray tube has an anode target spaced from an electron beam emitting structure which include a cathode, focusing electrode and a control electrode.
  • the control electrode surface nearest the anode is contoured to conform with selected equipotential values in the electrostatic field between the cathode and anode which equipotential is a predetermined percentage of the total cathode to anode voltage.
  • the control electrode is operated at a corresponding positive potential, the electrons follow certain trajectories and focus on the anode.
  • Means are provided for varying the control voltage through a range from beam cut-off voltage to various positive voltages that permit control of the focal spot size regardless of the selected beam current and selected anode voltage.
  • FIGS LENS-GRID SYSTEM FOR ELECTRON TUBES BACKGROUND OF THE INVENTION This invention pertains to electron tubes and will be exemplified in an x-ray generator tube.
  • the x-ray tube is usually provided with a focusing electrode to shape the electric field around the electron emitting filament for controlling the beam cross section so that a suitable focal spot is formed on the anode target.
  • the control electrode is usually operated at cathode potential for full electron beam current and is sometimes biased negatively when electron beam cutoff is desired.
  • the control electrode undesirably reduces the electric field strength in the vicinity of the cathode filament and an electron space charge which limits maximum available beam current results.
  • a general object of the present invention is to overcome the above noted disadvantages and to provide a more efiicient and more readily controllable electron emission device such as an x-ray tube.
  • the invention may be characterized briefly as a new lens-grid system for an electron tube such as an x-ray tube.
  • the new lens-grid system or cathode structure comprises a metal focusing electrode in which a cupshaped recess is formed.
  • the recess has a pair of spaced apart bottom slots in which there. are individual filaments, one for obtaining a high range of beam currents and the other for obtaining arelatively lower range of beam currents.
  • the filaments may be energized alternately.
  • a high gradient electric field is produced between the cathode and the target anode when the latter is energized at high voltages.
  • the anode voltage may range'from peak kilovolts (pkv) to l50pkv though sometimes the range extends to even lower and higher voltages.
  • equipotential lines or surfaces of the electric field can be measured and determined or plotted between the cathode and the anode. The configuration of the various equipotentials and the potential gradient governs the focusing efiect of the field.
  • the focusing cup electrode is established at the same potential as the cathode filament in which case the beam will focus on the target in a spot having predetermined width.
  • the potential of the focusing electrode is made very negative with respect to the filament.
  • a control electrode is located near the focusing electrode.
  • the control electrode surface most remote from the filament in the anode direction is made coincident with and in substantial contour conformation with a particular equipotential.
  • an equipotential representing a predetermined potential such as a relatively low percentage of the cathode to anode voltage, is chosen.
  • Variations of the potential on the control electrode permit enlarging or decreasing the width dimension of the beam and focal spot without requiring any anode potential change and without significantly affecting the total electron beam current.
  • the control electrode is made about half as negative as was heretofore required, the beam current is completely cut off.
  • the control electrode has no grid wires which could be imaged in the focal spot.
  • FIG. 1 is a longitudinal section view of a rotating anode x-ray tube with some parts omitted and which incorporates the new lens-grid system;
  • FIG. 2 is a plan view of the cathode structure or Iensgrid system taken along the line 2-2 in FIG. 1;
  • FIG. 3 is a section taken along the line 33 in FIG.
  • FIG. 4 is a section taken along the line 4-4 in FIG.
  • FIG. 5 is a section taken along the line 5-5 in FIG.
  • FIG. 6 is a schematic representation of the new lensgrid structure and showing the configuration and position of some of the equipotential lines;
  • FIG. 7 is a graph showing the relationship between the positive bias potential on the control electrode versus the focal spot width for two different focal spot sizes in a tube which uses the principles of the invention.
  • FIG. 8 is an electric circuit diagram for an x-ray tube in which the invention is incorporated.
  • FIG. 1 shows an x-ray generator or tube in which the new lens-grid structure is used.
  • the tube comprises a target or anode 10 which is mounted on a rotor 11 that is internally joumaled for rotation on a stem 12.
  • An extension 13 affords a place for connecting an anode voltage supply line.
  • Anode 10 has a beveled electron impact surface 14 on which an electron beam is focused in a spot from which x-rays emanate.
  • Spaced from target 10 is the new cathode structure or lens-grid which is generally designated by the number 15.
  • the cathode structure 15 is supported on a mounting device 16 that has a base annulus 17 whose edges are sealed into the ends of an annular reentrant glass section 18 that forms part of the evacuated x-ray tube envelope.
  • the midregion of the envelope comprises a thin metal shell 19 that is provided with a thin window 20, which may be metal or glass, through which the useful x-ray beam emanates from the focal spot on target surface 14.
  • Metal section 19 is sealed at one end into a glass tubular element 21 which joins sealingly at 22 with a mounting ferrule 23 for the rotating anode structure.
  • the conventional field coils for inducing rotor 11 to rotate are omitted from FIG. 1.
  • FIGS. 2-5 for a more detailed description of the cathode structure or lens-grid system 15.
  • the structure comprises a metal body 30 of substantially circular configuration.
  • Body 30 is herein called a first focusing electrode.
  • Focusing electrode 30 may experience as high as about 800 C during tube operation so it is desirable to make the body of a suitable temperature resistant metal such as nickel or molybdenum although other suitable refractory metals may be used.
  • the upper portion of electrode 30 is provided with a pair of slots 31 and 32. Slot 31 accommodates a large or heavy current filament 33 and slot 32 accommodates a smaller lower current filament 34.
  • the filaments are electrically isolated from the focusing electrode.
  • the slots may be spaced symmetrically from a diametral line that runs across the top of electrode 30 in a direction normal to the drawing where the numeral 35 is affixed in FIG. 3.
  • Slot 31 has diverging stepped walls 36 and 37 whose configuration has an effect on electrostatic field and equipotential line distribution in the vicinity of filament 33.
  • slot 32 has divergent stepped side walls 38 and 39 which serve the same purpose.
  • the open space between the topmost projections 40 and 41 in electrode 30 is characterized as a focusing cup or focusing electrode. In a single filament tube the diverging walls of the focusing cup recess would be symmetrical to the filament.
  • Electrode 45 is preferably cylindrical and has an annular side wall 46 and substantially planar portion 47. Portion 47 has a diametral or transverse slot in it and the sides or edges 48 and 49 of this slot diverge outwardly from each other with a particular contour or configuration that will be discussed in more detail later.
  • the slot is generally designated by the number 50.
  • a small rodlike element 51 which in this case is semicircular in cross section, extends lengthwise of the slot 50 and along its midline. The rod 51 should be as flat and thin as possible but it is made semicircular to obtain requisite strength. As can be seen in FIG.
  • rod 51 has one end 52 spotwelded to annulus 46 and has its other end 53 overlaid by a metal strip 54 whose opposite ends are also spotwelded to wall 46.
  • rod 51 is restrained from being removed but it can expand lengthwise under strip 54 when it is subjected to intense heat without developing internal stresses that would otherwise deform it.
  • Rod 51 participates in establishing the electrostatic field configuration involved in focusing and controlling each of the separately selected electron beams.
  • annular wall or rim 46 of control electron 45 is in concentric spaced relationship with the radially extending portion 55 of electrode body 30.
  • annular gap 56 is formed between portion 55 and wall 46 to isolate the control element 45 electrically from electrode 30.
  • the pin support construction afi'ords control electrode 45 and electrode 30 an opportunity to expand and contract thermally without generating undue internal stresses in either of these parts.
  • An advantage of the construction is that it obviates the need for matching the thermal expansion coefficients of the control element and focusing cup body in which case a wider choice of metals for making these components is allowed.
  • FIG. 6 shows schematically the geometrical relationship of the focusing electrode 30, the control electrode top surface 45, the electrode recess dividing rod 51 and the anode 10 with its electron impact target surface 14.
  • Filaments 33 and 34 are shown in their slots 31 and 32, respectively. Some of the electrostatic equipotential lines between the cathode structure and the anode are also illustrated. Note that the longitudinal axes of the filament wire coils 33 and 34 are in parallelism with electron impact surface 14 of anode 10 in FIG. 6. It is to obtain this parallelism that the cathode structure in FIG. 1 has its face nearest target surface 14 at an angle with respect to the longitudinal axis of the tube. In FIG.
  • Dividing rod 51 is also present in FIG. 6. As suggested earlier, rod 51 should preferably be flat and as thin as possible so as to lie in a plane coincident with the plane of the equipotential surface which represents a potential equal to a predetermined percent of the cathode to anode potential.
  • the solid equipotential lines 80-86 are those that exist when the lens-grid 45 is biased to a potential equal to the equipotential value of the line that coincides with the contour of its surfaces 48 and 49.
  • the electron beam emitted from either of the cathode filaments 33 or 34 will focus on anode surface 14 with a predetermined spot size and the trajectory of the electrons will not be affected by the selected equipotential.
  • the particular equipotential plot shown in FIG. 6 represents the case. where 5% of the cathode to anode voltage is applied between lens-grid 45 and the filaments 33 and 34.
  • the values of the equipotential lines in terms of percent of cathode to anode voltage are also applied to solid lines 80-86.
  • Equipotential lines between of cathode to anode voltage and l00% are omitted from the plot in FIG. 6.
  • the omitted lines gradually become more straight than the 20% line 86 and eventually become substantially parallel to the anode surface 14 and to each other.
  • the equipotential plot has been obtained by methods that are familiar to those skilled in the electron tube arts and need not be described in detail.
  • the lens-grid 45 could also be formed to have its contoured surfaces 48 and 49 and the straighter surfaces confluent therewith to coincide with some other equipotential line such as the 7.5% line or something under 5% such as the 4% or 3% lines which are not shown.
  • a bias potential equal in value to the equipotential to obtain the result that the trajectories of the electrons traversing the field will not be altered by the equipotential surface coincident with the surface of the lens-grid.
  • FIG. 6 the normal 6% equipotential existing when 5% bias voltage is applied to lens-grid 45 is shown partially as a dash-dot-dot line 87.
  • the purpose is to illustrate what happens when the bias voltage on the lensgrid is changed to 6% of the cathode to anode voltage in a case where the contour of the lens-grid coincides with the 5% equipotential.
  • the 6% equipotential shifts to partially follow the contours of surfaces 48 and 49 which are equipotential and to further assume the shape of the dash-dot line 88.
  • the actual result is that cathode filament 33 comes under a more positive influence.
  • the field strength presented to the emitting filament 33 or 34 is increased and an increase in the maximum available beam current results provided the filament is not being operated in an emission or temperature limited mode.
  • x-ray tubes are usually operated in a filament temperature limited emission condition and there is usually substantial space charge but the operative effect of increasing the positive potential on lens-grid 45 according to the invention permits changing focal spot width without significantly altering target current or target voltage which is a desired objective of the invention.
  • An important aspect of having the contour of the lens-grid electrode 45 coincide with a selected equipotential is that positive control voltages may be applied to the lens-grid 45 without substantial electron current flowing to it.
  • beam current is not diminished as a result of grid control nor is consequential grid heating experienced as was the case in prior art grid controlled tubes.
  • a grid current of only 600 microamperes was measured when the tube was conducting 1,800 milliamperes of electron current between the cathode and anode even though the lens-grid was positive with respect to the active filament.
  • the new lens-grid system permits complete current cutoff from the x-ray tube when it is operating at high cathode to anode potentials.
  • the largest focal spot size with cutoff bias capability was typically 1.2mm size since switching bias voltages of greater than 5 kilovolts in the millisecond exposure times was considered impractical.
  • a negative bias voltage of kilovolts was required to cutoff a focal spot size of 1.2mm.
  • FIG. 7 is a graph of positive bias potential applied to the lens-grid in terms of percent of voltage between the cathode and anode of the tube versus spot width in millimeters in which tube the new lens-grid system was used. Note that the large spot width produced by the beam from filament 33 was varied from under 2mm to over 3mm at constant cathode to anode voltage and constant beam current. The small focal spot which is represented by line 92 was varied from about 0.5 to over 2mm where the bias potential was changed from about 3 to 5.5% of cathode to anode voltage.
  • the means for selecting one or the other of the filaments are not shown but it will be understood by those skilled in the art that when a high current beam is desired such as for various radiographic technics, large filament 33 will be energized. When low beam current is desired such as for fluoroscopy, filament 34 will be selectively energized to the exclusion of the other filament. It will also be understood that the equipotential plot shown in FIG. 6 and discussed primarily in respect to use of filament 33 is symmetrical so that what has been said applies equally as well to use of filament 34.
  • FIG. 8 is a schematic diagram for illustrating how an x-ray generator using the new lens-grid is operated. Only one cathode or electron emitter 33 is shown for the sake of simplicity since the electrical connections are the same for the other selectable emitter 34.
  • the target anode is marked 10
  • the focusing cup electrode is marked 30
  • the lens-grid electrode is marked 45 as they are in the previously discussed figures.
  • Two bias voltage sources 102 and 103 are shown in block form. These sources are connected to the electrodes through a double pole, double throw switch 104 which is symbolized as a mechanical switch although various types of switches may be used.
  • Potential for accelerating electrons from cathode 33 to target anode 10 may be applied across terminal 105 and 106 with the potential on terminal 105 being negative and below ground potential by as much as the absolute value of the potential on terminal 106 is positive or above ground potential.
  • a ground or midpoint potential terminal is shown. Midpoint is obtained from the center tap of the high voltage transformer which is not shown since it is of a known type.
  • the metal shell 19 of the x-ray tube shown in FIG. 1 may be established at ground potential.
  • bias source 102 makes lens-grid 45 positive with respect to cathode 33 and focusing electrode 30 and full electron beam current flows to anode 10. Adjustment of bias source 102 permits attainment of different selected focal spot sizes in accordance with the level of positive potential on lens-grid electrode 45 as described in detail hereinbefore.
  • Switching switch 104 to its alternate state applies voltage from bias source 103 to lens-grid 45 and focusing electrode 30 at the same time so that these electrodes are both negative with respect to emitter 33 and electron flow to anode 10 is cut off.
  • a negative potential of about 3500 volts will effectuate cutoff even when the anode 10 to cathode 33 potential is 150 kvp.
  • An x-ray generator comprising:
  • cathode means including electron emitter means whose electron emission is limited and controlled primarily by the selected temperature of said emitter means and whose electron emission available for forming an electron beam is subject to further limitation by space charge in the vicinity of said emitter means,
  • said cathode means including first field forming electrode means adjacent said emitter means for focusing emitted electrons into a beam in response to a potential on said first electrode means,
  • target anode means spaced from said emitter means and having a surface arranged to be impacted by said beam to produce x-radiation, said surface being at the equipotential and said emitter means being at the 0% equipotential among equipotentials caused by applying a positive potential to said target anode relative to said emitter means,
  • said second electrode means being the sole electrode between said field forming electrode means and said target anode means and comprising an element having a surface disposed generally transversely to said beam and having an opening for passage of said beam, f. said last named surface and portions of the margins of said opening being other than planar and coinciding and conforming substantially with a selected equipotential which is other than planar and has a value in the rang fe'of 1 t'o,1"5% or the potential difference between said target anode and said cathodemeans,
  • said first electrode means has a plurality of holes therein
  • said second electrode has a portion surrounding said first electrode means in spaced relation therewith, said second electrode means having holes presented toward the holes in said first electrode means, and
  • insulating pin means extending from within said holes in said first electrode means to within holes in said second electrode means for supporting said second electrode means from said first electrode means.
  • said first field forming electrode means has at least two transverse recesses and oppositely diverging side walls defining the same for shaping said electric field
  • said emission means comprising an elongated filament in each of said recesses.
  • said second control electrode means has at least two transverse recesses and oppositely diverging side walls defining the same for shaping said electric field
  • said emission means comprising an elongated filament in each of said recesses
  • rod means coextensive with said opening and intermediate the sides thereof and between said emission means and disposed substantially on said selected equipotential.
  • said second control electrode is located substantially coincident with an equipotential whose value is in the range of 1% to 15% of the potential between said cathode and anode means.
  • An electron discharge device comprising:
  • said cathode means including a first field forming electrode means and means for emitting electrons
  • a second electrode means electrically isolated from and spaced from said first electrode in the direction of said anode and disposed generally transversely to the path for an electron beam from said means for emitting electrons to said anode
  • said second electrode means comprising a surface having an opening therein which surface substantially conforms to a selected equipotential through which electrons from said emitting means may pass with the trajectories of said electrons being subi l stantially unaltered whereby when said second electrodemeans is energized with a positive potential substantially equal to said equipotential it will "permit substantially unintercepted passage of electrons through said opening, i
  • said first electrode means having a cylindrical portion and said second electrode means having a portion circumjacent to said first electrode means and in spaced relationship therewith, and
  • An x-ray generator comprising:
  • second control electrode means interposed between said first electrode means and said target anode means and including a conductive member disposed generally transversely to the path of said electron beam and having an opening therein, said member having a surface presented toward said target anode means,
  • said opening being defined by a margin surface which together with said surface of said member substantially conform with a selected equipotential existing when there is a positive potential on said anode means relative to said first electrode means, said selected equipotential being one across which electrons may pass with their trajectories being substantially unaltered, whereby said second electrode means is adapted to be energized with a positive potential relative to said second electrode means which positive potential is substantially equal in magnitude to said selected equipotential such that it will permit substantially unintercepted passage of electrons through said opening,
  • said first field forming electrode means having at least two recesses each of which has generally diverging sides
  • said electron emission means being disposed in said recesses, respectively, and
  • a conductive rod means extending across the opening in said second electrode means and aligned intermediately of said recesses, said rod means being electrically connected with said second electrode means.
  • An x-ray generator comprising:
  • second control electrode means interposed between said first electrode means and said target anode means and including a conductive member disposed generally transversely to the path of said electron beam and having an opening therein, said member having a surface presented toward said target anode means,
  • said opening being defined by a margin surface
  • said second electrode-means includes an annular part which is enclosed on one end by said transversely disposed member, said annular part surrounding said first field forming electrode means and being in substantial concentric spaced relationship therewith,
  • insulating pin means which each have corresponding ends engaged with said first electrode means and opposed corresponding ends engaged with said annular portion of said second electrode means for supporting said second elec trode means from said first electrode means.

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US466728A 1974-05-03 1974-05-03 Lens-grid system for electron tubes Expired - Lifetime US3916202A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
US466728A US3916202A (en) 1974-05-03 1974-05-03 Lens-grid system for electron tubes
CA224,695A CA1034181A (en) 1974-05-03 1975-04-14 Lens-grid system for x-ray generating electron tube
DE2518688A DE2518688C2 (de) 1974-05-03 1975-04-26 Röntgenröhre
ES437333A ES437333A1 (es) 1974-05-03 1975-04-30 Un generador de rayos x.
FR7513522A FR2286499A1 (fr) 1974-05-03 1975-04-30 Appareil a decharge electronique
IT22870/75A IT1037741B (it) 1974-05-03 1975-04-30 Sistema di lente a griglia per tubi elettronici specialmente per tubi a raggi x
CH564475A CH614313A5 (de) 1974-05-03 1975-05-02
BE156016A BE828673A (fr) 1974-05-03 1975-09-01 Appareil a decharge electronique

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US466728A US3916202A (en) 1974-05-03 1974-05-03 Lens-grid system for electron tubes

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US3916202A true US3916202A (en) 1975-10-28

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US (1) US3916202A (de)
BE (1) BE828673A (de)
CA (1) CA1034181A (de)
CH (1) CH614313A5 (de)
DE (1) DE2518688C2 (de)
ES (1) ES437333A1 (de)
FR (1) FR2286499A1 (de)
IT (1) IT1037741B (de)

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DE3136881A1 (de) * 1980-09-29 1982-05-19 General Electric Co., Schenectady, N.Y. "anordnung zum erzeugen einer veraenderbaren vorspannung fuer eine roentgenroehre"
FR2513061A1 (fr) * 1981-06-12 1983-03-18 Thomson Csf Dispositif de polarisation multiple de cathode de tube a rayons x et source radiogene comportant un tel dispositif
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EP0283039A2 (de) * 1987-03-19 1988-09-21 Siemens Aktiengesellschaft Röntgenröhre
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WO2003044823A1 (en) * 2001-11-20 2003-05-30 Koninklijke Philips Electronics Nv X-ray tube cathode cup structure for focal spot deflection
US6801599B1 (en) 2001-11-20 2004-10-05 Koninklijke Philips Electronics, N.V. X-ray tube cathode cup structure for focal spot deflection
US20050175152A1 (en) * 2004-02-09 2005-08-11 Varian Medical Systems Technologies, Inc. Cathode head with focal spot control
US20090154649A1 (en) * 2006-05-22 2009-06-18 Koninklijke Philips Electronics N.V. X-ray tube whose electron beam is manipulated synchronously with the rotational anode movement
WO2010061332A1 (en) 2008-11-26 2010-06-03 Philips Intellectual Property & Standards Gmbh Auxiliary grid electrode for x-ray tubes
US20100277051A1 (en) * 2009-04-30 2010-11-04 Scientific Instrument Services, Inc. Emission filaments made from a rhenium alloy and method of manufacturing thereof
DE19739839B4 (de) * 1996-09-17 2013-11-28 General Electric Co. Kathodenbecheranordnung für eine Röntgenröhre und Verfahren zum Zusammenbauen einer Kathodenbecheranordnung
US20150117617A1 (en) * 2012-07-02 2015-04-30 Kabushiki Kaisha Toshiba X-ray tube
CN106158563A (zh) * 2016-08-31 2016-11-23 成都凯赛尔电子有限公司 一种2.5mm焦点的螺旋阴极聚焦方法
US9524845B2 (en) 2012-01-18 2016-12-20 Varian Medical Systems, Inc. X-ray tube cathode with magnetic electron beam steering
RU168725U1 (ru) * 2016-09-09 2017-02-17 Общество с ограниченной ответственностью Совместное русско-французское предприятие "СпектрАп" Рентгеновская диагностическая трубка
US20170250051A1 (en) * 2016-02-29 2017-08-31 General Electric Company Robust Electrode With Septum Rod For Biased X-Ray Tube Cathode
CN110676144A (zh) * 2019-09-17 2020-01-10 中国科学院国家空间科学中心 一种x射线管阴极结构
US20230197397A1 (en) * 2021-12-21 2023-06-22 GE Precision Healthcare LLC X-ray tube cathode focusing element

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DE3107949A1 (de) * 1981-03-02 1982-09-16 Siemens AG, 1000 Berlin und 8000 München Roentgenroehre
US4764947A (en) * 1985-12-04 1988-08-16 The Machlett Laboratories, Incorporated Cathode focusing arrangement

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DE3136881A1 (de) * 1980-09-29 1982-05-19 General Electric Co., Schenectady, N.Y. "anordnung zum erzeugen einer veraenderbaren vorspannung fuer eine roentgenroehre"
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FR2513061A1 (fr) * 1981-06-12 1983-03-18 Thomson Csf Dispositif de polarisation multiple de cathode de tube a rayons x et source radiogene comportant un tel dispositif
US4559640A (en) * 1981-06-12 1985-12-17 Thomson-Csf X-Ray tube cathode multiple polarization device and a radiation source incorporating such a device
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EP0273162A3 (en) * 1986-12-31 1989-02-15 General Electric Company Two-piece cathode cup
EP0273162A2 (de) * 1986-12-31 1988-07-06 General Electric Company Zweigeteilte Becherkathode
US4894853A (en) * 1987-03-19 1990-01-16 Siemens Medical Systems, Inc. Cathode cup improvement
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EP0283039A2 (de) * 1987-03-19 1988-09-21 Siemens Aktiengesellschaft Röntgenröhre
US5044005A (en) * 1988-07-01 1991-08-27 General Electric Cgr S.A. X-ray tube with a flat cathode and indirect heating
FR2633775A1 (fr) * 1988-07-01 1990-01-05 Gen Electric Cgr Tube radiogene a cathode plane et a chauffage indirect
EP0349387A1 (de) * 1988-07-01 1990-01-03 General Electric Cgr S.A. Röntgenröhre mit flacher Kathode und indirekter Heizung
US5543625A (en) * 1994-05-20 1996-08-06 Finnigan Corporation Filament assembly for mass spectrometer ion sources
DE19739839B4 (de) * 1996-09-17 2013-11-28 General Electric Co. Kathodenbecheranordnung für eine Röntgenröhre und Verfahren zum Zusammenbauen einer Kathodenbecheranordnung
US6438207B1 (en) 1999-09-14 2002-08-20 Varian Medical Systems, Inc. X-ray tube having improved focal spot control
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US6888922B2 (en) * 2001-10-18 2005-05-03 Ge Medical Systems Global Technology Co., Llc Filament circuit resistance adjusting apparatus technical field
WO2003044823A1 (en) * 2001-11-20 2003-05-30 Koninklijke Philips Electronics Nv X-ray tube cathode cup structure for focal spot deflection
US6801599B1 (en) 2001-11-20 2004-10-05 Koninklijke Philips Electronics, N.V. X-ray tube cathode cup structure for focal spot deflection
US20050175152A1 (en) * 2004-02-09 2005-08-11 Varian Medical Systems Technologies, Inc. Cathode head with focal spot control
US7257194B2 (en) 2004-02-09 2007-08-14 Varian Medical Systems Technologies, Inc. Cathode head with focal spot control
US20090154649A1 (en) * 2006-05-22 2009-06-18 Koninklijke Philips Electronics N.V. X-ray tube whose electron beam is manipulated synchronously with the rotational anode movement
US8498380B2 (en) 2008-11-26 2013-07-30 Koninklijke Philips N.V. Auxiliary grid electrode for X-ray tubes
WO2010061332A1 (en) 2008-11-26 2010-06-03 Philips Intellectual Property & Standards Gmbh Auxiliary grid electrode for x-ray tubes
CN102224560B (zh) * 2008-11-26 2015-08-05 皇家飞利浦电子股份有限公司 用于x射线管的辅助格栅电极
US20110235785A1 (en) * 2008-11-26 2011-09-29 Koninklijke Philips Electronics N.V. Auxiliary grid electrode for x-ray tubes
CN102224560A (zh) * 2008-11-26 2011-10-19 皇家飞利浦电子股份有限公司 用于x射线管的辅助格栅电极
US8134290B2 (en) 2009-04-30 2012-03-13 Scientific Instrument Services, Inc. Emission filaments made from a rhenium alloy and method of manufacturing thereof
US20100277051A1 (en) * 2009-04-30 2010-11-04 Scientific Instrument Services, Inc. Emission filaments made from a rhenium alloy and method of manufacturing thereof
US8226449B2 (en) 2009-04-30 2012-07-24 Scientific Instrument Services, Inc. Method of manufacturing rhenium alloy emission filaments
US9524845B2 (en) 2012-01-18 2016-12-20 Varian Medical Systems, Inc. X-ray tube cathode with magnetic electron beam steering
US20150117617A1 (en) * 2012-07-02 2015-04-30 Kabushiki Kaisha Toshiba X-ray tube
US9653248B2 (en) * 2012-07-02 2017-05-16 Toshiba Electron Tubes & Devices Co., Ltd. X-ray tube
US20170250051A1 (en) * 2016-02-29 2017-08-31 General Electric Company Robust Electrode With Septum Rod For Biased X-Ray Tube Cathode
US10032595B2 (en) * 2016-02-29 2018-07-24 General Electric Company Robust electrode with septum rod for biased X-ray tube cathode
CN106158563A (zh) * 2016-08-31 2016-11-23 成都凯赛尔电子有限公司 一种2.5mm焦点的螺旋阴极聚焦方法
RU168725U1 (ru) * 2016-09-09 2017-02-17 Общество с ограниченной ответственностью Совместное русско-французское предприятие "СпектрАп" Рентгеновская диагностическая трубка
CN110676144A (zh) * 2019-09-17 2020-01-10 中国科学院国家空间科学中心 一种x射线管阴极结构
CN110676144B (zh) * 2019-09-17 2022-01-21 中国科学院国家空间科学中心 一种x射线管阴极结构
US20230197397A1 (en) * 2021-12-21 2023-06-22 GE Precision Healthcare LLC X-ray tube cathode focusing element
US12046441B2 (en) * 2021-12-21 2024-07-23 GE Precision Healthcare LLC X-ray tube cathode focusing element

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CA1034181A (en) 1978-07-04
IT1037741B (it) 1979-11-20
FR2286499B1 (de) 1982-08-20
BE828673A (fr) 1975-09-01
DE2518688C2 (de) 1987-01-29
ES437333A1 (es) 1977-10-01
FR2286499A1 (fr) 1976-04-23
DE2518688A1 (de) 1975-11-13
CH614313A5 (de) 1979-11-15

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