US3392304A - Power supply for an electron beam furnace gun - Google Patents

Power supply for an electron beam furnace gun Download PDF

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Publication number
US3392304A
US3392304A US497801A US49780165A US3392304A US 3392304 A US3392304 A US 3392304A US 497801 A US497801 A US 497801A US 49780165 A US49780165 A US 49780165A US 3392304 A US3392304 A US 3392304A
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US
United States
Prior art keywords
electron beam
current
electron gun
diode
power supply
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
US497801A
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English (en)
Inventor
Anderson Emmett Raymond
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.)
Airco Inc
Original Assignee
Air Reduction Co Inc
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 Air Reduction Co Inc filed Critical Air Reduction Co Inc
Priority to US497801A priority Critical patent/US3392304A/en
Priority to GB37672/66A priority patent/GB1085107A/en
Priority to BE686294D priority patent/BE686294A/xx
Priority to FR76297A priority patent/FR1492625A/fr
Priority to LU52182A priority patent/LU52182A1/xx
Priority to DK537466AA priority patent/DK126144B/da
Priority to NL6614666A priority patent/NL6614666A/xx
Priority to CH1503266A priority patent/CH452075A/de
Priority to ES0332397A priority patent/ES332397A1/es
Priority to AT973266A priority patent/AT279914B/de
Application granted granted Critical
Publication of US3392304A publication Critical patent/US3392304A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
    • B05B7/14—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas designed for spraying particulate materials
    • B05B7/1404—Arrangements for supplying particulate material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B13/00—Machines or plants for applying liquids or other fluent materials to surfaces of objects or other work by spraying, not covered by groups B05B1/00 - B05B11/00
    • B05B13/02—Means for supporting work; Arrangement or mounting of spray heads; Adaptation or arrangement of means for feeding work
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/02—Details
    • H01J37/24—Circuit arrangements not adapted to a particular application of the tube and not otherwise provided for
    • H01J37/243—Beam current control or regulation circuits

Definitions

  • the present invention relates generally to power supplies and more particularly to a power supply which is adaptable for supplying several kilowatts of power to an electron beam gun employed in a high vacuum electron beam furnace.
  • Electron beam furnaces may be utilized in numerous situations particularly where material treating operations are to be conducted. Typical examples of such operations which are now quite well known include high temperature melting and purification of various materials, vapor plating, cleaning, etc.
  • the electron beam furnace employed in such operations comprises an electron gun disposed in an evacuated enclosure together with the material to be treated.
  • the electron gun typically is provided with an electron emitting cathode or filament and an accelerating anode, which is maintained at a high positive potential with respect to the cathode so as to establish the high electrostatic field for accelerating the electrons.
  • the cathode When the cathode is sufliciently energized and the requisite electrostatic field is established a high intensity beam of electrons is emitted from the electron gun and may be directed to bombard the material, thereby heating the same. Obviously the amount of heating effected is related to the intensity of the electron beam current together with the accelerating voltage applied by the field through which the electrons travel.
  • Apparatus has been developed for alleviating the aforementioned eifects as well as regulating the power supplied to the electron gun. Certain of such apparatus, during normal operation, maintains the voltage at a generally constant level, and when arcing occurs limits the current supplied to a preselected level. Such apparatus has been relatively complex. I Other apparatus has been developed which controls or maintains constant the current supplied to an electron gun. Such apparatus normally employ monocyclic power supplies which usually include inductors and capacitors connected so as to provide resonant circuits which resonate at the frequency of the input circuit. But, extensive means are ordinarily provided in such circuits for protecting the various elements against overstress. In addition, reactive elements of uneconomica'lly large size are often required.
  • Another object of the invention is the provision of a power supply for an electron beam furnace which limits the effects of arcing in the electron beam.
  • Still another object is the provision of a power supply for an electron beam gun which limits the maximum current supplied to the gun under are discharge conditions.
  • a further object is the provision of an electron beam gun power supply which is relatively economical to manufacture, durable in use and which aids in prolonging the useful life of the electron gun structure.
  • FIGURE 1 is a schematic circuit diagram of one embodiment of a power supply in accordance with the present invention.
  • FIGURE 2 is a graph showing typical characteristic curves of a power diode suitable for use in the circuit illustrated in FIGURE 1.
  • the current supplied by an electron gun 10 in an electron furnace 12 is limited to a preselected level by employing a diode 14 connected in series with the output of a D-C power supply 16 and the electron beam of the gun 10.
  • a diode 14 connected in series with the output of a D-C power supply 16 and the electron beam of the gun 10.
  • the high voltage D-C power supply 16 may be a conventional three phase, full wave rectifier which is connected through suitable leads 18 to a source of three phase A-C power (not shown).
  • the positive output terminal 20 of the power supply 16 is grounded and the negative terminal 22 of the power supply 16 is coupled through a conductor 24 to the filament 26 of the diode 14.
  • the diode has a directly heated filament which is heated by a filament transformer 28.
  • a primary winding 30 of the filament transformer 28 is connected to a first variable autotransformer 32, which is connected to a single phase of the A-C power supply.
  • a secondary winding 34 of the filament transformer 28 is coupled to the filament 26 of the diode 14.
  • the filament transformer 28 is preferably provided with high voltage insulation on its windings since there is generally a substantial ditference between the voltage on the windings.
  • the anode 36 of the diode 14 is coupled through a conductor 38 to the cathode 40 of the electron gun 10 which may be of the conventional type.
  • the cathode 40 of the electron gun 10 is energized by a filament transformer 42.
  • the filament transformer 42 includes a primary winding 44 connected to a second variable autotransformer 46 which is connected to the single phase of the AC power supply.
  • the filament transformer 42 further includes a secondary winding 47 coupled to the cathode 40.
  • the windings of the filament transformer 42 are also preferably provided with high voltage insulation.
  • the accelerating anode 48 of the electron gun is suitably grounded so that the requisite high voltage or accelerating potential is applied between the cathode 40 and the accelerating anode 48 of the gun 10.
  • the electron gun 10 is suitably disposed within the appropriately grounded electron beam furnace 12 so that the electron beam is directed upwardly and is deflected onto the suitably grounded target material 52 by a transverse magnetic field established by a suitable magnet 53 disposed within the furnace 12 together with the electron gun 10 and the target material 52.
  • the furnace includes a suitable vacuum pump 54 for maintaining the necessary vacuum.
  • a complete series circuit is defined extending from the grounded positive terminal of the power supply 16 through the negative terminal 22, through the diode 14, and through the electron beam emitted by the cathode 40 to the grounded accelerating anode 48.
  • the diode 14 is electrically in series relationship with the electron beam and accordingly may be appropriately adjusted to limit the electron beam current, as is hereinafter explained in detail.
  • the beam current is adjusted by adjusting the voltage applied across the primary winding 44. This is achieved by appropriate adjustment of the second variable autotransformer 46.
  • the maximum beam current which can flow through the electron gun is set by selecting the level of operation of the diode.
  • the desired maximum level of the control diode 14 is selected by means of the first variable autotransformer 32, which controls the filament current of the diode 14.
  • the particular power diode 14 is selected to supply the required maximum current to the electron gun.
  • a power diode of the type having a substantially pure tungsten filament is generally employed.
  • the characteristic curves at several levels of filament current of a typical power diode suitable for use in a power supply in accordance with the present invention are illustrated in FIGURE 2.
  • the maximum diode current as measured along the horizontal axis increases as the filament current (I;) increases, but reaches a maximum value for each particular value of If as shown by the intersection of each curve with the base line 55.
  • I the current passing through the tube and correspondingly the electron beam current
  • the second autotransformer 46 may be conveniently adjusted by adjusting the second autotransformer 46 to cause the electron beam current to vary from zero amps, as shown by the point designated by the numeral 56, to the point designated by the numeral 58, at which the emission current of the particular tube at this level of filament current is approached.
  • a desired current which is less than the maximum diode current at the selected level of operation, may be drawn from the anode 36 of the diode 14 by adjusting the filament current, supplied to the cathode 40 of the electron gun.
  • the voltage drop across the diode which is a relatively low proportion of the D-C supply voltage, increases at a relatively low rate remaining substantially constant with increasing diode current.
  • the remainder of the supply voltage thus, is developed across the electron gun 10, providing a constant high accelerating potential for the electron beam as the electron beam current is varied.
  • the voltage across the electron gun 10 is accordingly regulated or held substantially constant during normal operation as the electron beam current is varied.
  • the disclosed power supply is provided with a protective feature which limits the maximum current level which can be reached by the electron beam.
  • This current level is generally dictated by the emission characteristics of a diode con nected in series relationship with the electron gun.
  • the voltage developed across the electron gun is maintained substantially constant, or regulated, as the electron beam current is varied within the preselected limits determined by the diode characteristics.
  • a plurality of diodes may be connected to a common power supply and coupled to a plurality of electron guns. This may be conveniently achieved since there is a common ground return for the total emission current passing through each tube to the electron guns and thence to the grounded target material.
  • an improved and substantially simplified power supply has been provided in which, after selecting a particular maximum current level by adjusting the filament temperature of the diode, a single control is adjusted for varying the electron beam current over its preselected operating range.
  • the voltage developed across the electron gun is regulated during normal operation while the beam current may vary, and an automatic protective feature is provided for limiting the maximum electron beam current to a preselected value regardless of abrupt decreases in the resistance of the electron beam path such as may result from arcing.
  • Apparatus for controlling the electron beam current supplied by an electron gun and directed at a target material in an electron beam furnace comprising means for supplying a direct current voltage to said electron gun and a diode serially coupled between said direct current voltage supply means and said electron gun for lim iting the current conducted therethrough.
  • Apparatus for controlling the electron beam current supplied by an electron gun and directed at a target material in an electron beam furnace comprising means for supplying a direct current voltage to said electron gun, a diode serially connected between said voltage supply means and said electron gun for limiting the current conducted therethrough, said diode having a heated filament, and means coupled to said heated filament for adjusting the current supplied thereto.

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  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Electron Sources, Ion Sources (AREA)
  • Treatments Of Macromolecular Shaped Articles (AREA)
US497801A 1965-10-19 1965-10-19 Power supply for an electron beam furnace gun Expired - Lifetime US3392304A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
US497801A US3392304A (en) 1965-10-19 1965-10-19 Power supply for an electron beam furnace gun
GB37672/66A GB1085107A (en) 1965-10-19 1966-08-23 Improvements in or relating to power supply
BE686294D BE686294A (enrdf_load_stackoverflow) 1965-10-19 1966-09-01
FR76297A FR1492625A (fr) 1965-10-19 1966-09-14 Appareil d'alimentation réglable pour canon à électrons
LU52182A LU52182A1 (enrdf_load_stackoverflow) 1965-10-19 1966-10-17
DK537466AA DK126144B (da) 1965-10-19 1966-10-18 Apparat til regulering af elektronstrålestrømmen i en elektronstråleovn.
NL6614666A NL6614666A (enrdf_load_stackoverflow) 1965-10-19 1966-10-18
CH1503266A CH452075A (de) 1965-10-19 1966-10-18 Elektronenstrahlofen mit Vorrichtung zur Steuerung des Stromes eines Elektronenstrahles
ES0332397A ES332397A1 (es) 1965-10-19 1966-10-18 Aparato para controlar la corriente del haz electronico suministrada por una cañon electronico y dirigida a un material objetivo dentro de un horno de haz electronico.
AT973266A AT279914B (de) 1965-10-19 1966-10-19 Schaltung zur Begrenzung des auf ein Zielmaterial gerichteten und von einer Elektronenschleuder emittierten Elektronenstrahlstromes in einem Elektronenstrahlofen

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US497801A US3392304A (en) 1965-10-19 1965-10-19 Power supply for an electron beam furnace gun

Publications (1)

Publication Number Publication Date
US3392304A true US3392304A (en) 1968-07-09

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US497801A Expired - Lifetime US3392304A (en) 1965-10-19 1965-10-19 Power supply for an electron beam furnace gun

Country Status (9)

Country Link
US (1) US3392304A (enrdf_load_stackoverflow)
AT (1) AT279914B (enrdf_load_stackoverflow)
BE (1) BE686294A (enrdf_load_stackoverflow)
CH (1) CH452075A (enrdf_load_stackoverflow)
DK (1) DK126144B (enrdf_load_stackoverflow)
ES (1) ES332397A1 (enrdf_load_stackoverflow)
GB (1) GB1085107A (enrdf_load_stackoverflow)
LU (1) LU52182A1 (enrdf_load_stackoverflow)
NL (1) NL6614666A (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4936960A (en) * 1989-01-03 1990-06-26 Advanced Energy Industries, Inc. Method and apparatus for recovery from low impedance condition during cathodic arc processes
US4943325A (en) * 1988-10-19 1990-07-24 Black & Veatch, Engineers-Architects Reflector assembly
US4963238A (en) * 1989-01-13 1990-10-16 Siefkes Jerry D Method for removal of electrical shorts in a sputtering system
US6007879A (en) * 1995-04-07 1999-12-28 Advanced Energy Industries, Inc. Adjustable energy quantum thin film plasma processing system
US20090065045A1 (en) * 2007-09-10 2009-03-12 Zenith Solar Ltd. Solar electricity generation system
US9893223B2 (en) 2010-11-16 2018-02-13 Suncore Photovoltaics, Inc. Solar electricity generation system

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2912616A (en) * 1956-02-07 1959-11-10 Itt Pulsed-cathode electron gun
US2994801A (en) * 1959-06-05 1961-08-01 Stauffer Chemical Co Electron beam generation
US3172007A (en) * 1962-01-15 1965-03-02 Stauffer Chemical Co Folded filament beam generator

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2912616A (en) * 1956-02-07 1959-11-10 Itt Pulsed-cathode electron gun
US2994801A (en) * 1959-06-05 1961-08-01 Stauffer Chemical Co Electron beam generation
US3172007A (en) * 1962-01-15 1965-03-02 Stauffer Chemical Co Folded filament beam generator

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4943325A (en) * 1988-10-19 1990-07-24 Black & Veatch, Engineers-Architects Reflector assembly
US4936960A (en) * 1989-01-03 1990-06-26 Advanced Energy Industries, Inc. Method and apparatus for recovery from low impedance condition during cathodic arc processes
US4963238A (en) * 1989-01-13 1990-10-16 Siefkes Jerry D Method for removal of electrical shorts in a sputtering system
US6007879A (en) * 1995-04-07 1999-12-28 Advanced Energy Industries, Inc. Adjustable energy quantum thin film plasma processing system
US6368477B1 (en) 1995-04-07 2002-04-09 Advanced Energy Industries, Inc. Adjustable energy quantum thin film plasma processing system
US20090065045A1 (en) * 2007-09-10 2009-03-12 Zenith Solar Ltd. Solar electricity generation system
US9893223B2 (en) 2010-11-16 2018-02-13 Suncore Photovoltaics, Inc. Solar electricity generation system

Also Published As

Publication number Publication date
DK126144B (da) 1973-06-12
BE686294A (enrdf_load_stackoverflow) 1967-02-15
NL6614666A (enrdf_load_stackoverflow) 1967-04-20
ES332397A1 (es) 1967-08-01
AT279914B (de) 1970-03-25
CH452075A (de) 1968-05-31
GB1085107A (en) 1967-09-27
LU52182A1 (enrdf_load_stackoverflow) 1966-12-19

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