US3655902A - Heating system for electron beam furnace - Google Patents

Heating system for electron beam furnace Download PDF

Info

Publication number
US3655902A
US3655902A US81720A US3655902DA US3655902A US 3655902 A US3655902 A US 3655902A US 81720 A US81720 A US 81720A US 3655902D A US3655902D A US 3655902DA US 3655902 A US3655902 A US 3655902A
Authority
US
United States
Prior art keywords
electron beam
pole pieces
magnetic field
plane
path
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
US81720A
Other languages
English (en)
Inventor
Alexander H Firestone
Robert W Fisk
Kurt D Kennedy
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
Application granted granted Critical
Publication of US3655902A publication Critical patent/US3655902A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01J37/30—Electron-beam or ion-beam tubes for localised treatment of objects
    • H01J37/305—Electron-beam or ion-beam tubes for localised treatment of objects for casting, melting, evaporating, or etching
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/16—Remelting metals
    • C22B9/22—Remelting metals with heating by wave energy or particle radiation
    • C22B9/228—Remelting metals with heating by wave energy or particle radiation by particle radiation, e.g. electron beams

Definitions

  • FIG.4 1 flnmwfl m N70 M mmr w M A k! FIG.4
  • HEATING SYSTEM FOR ELECTRON BEAM FURNACE This invention relates generally to electron beam furnaces and, more particularly, to an improved heating system in such afurnace.
  • Electron beam furnaces of a variety of designs are useful in the processing of many metals, alloys or other materials, for example where high standards of purity are to be achieved by outgassing or by avoiding reaction with oxygen and nitrogen, or where a substrate is to be coated by vaporization and condensation of the material. Electron beams are aparticularly useful form of heating in that it is possible to inject heat into a melt locally. Electron beam furnaces typically include an evacuated enclosure, a heating system comprising one or more electron beam guns with associated deflection means for directing and focusing the beams, and a container for the molten material being processed.
  • the container for the molten material may take a variety of forms.
  • a typical container consists of an open topped upright crucible. Electron beam heating enables the crucible itself to be cooled and thereby form a skull of solidified molten material between the crucible and the molten material. This protects the purity of the molten material and makes it unnecessary to use high temperature refractories for the crucible constructron.
  • Another type of processing is the purification of metals and alloys bypassing the molten material or alloy over a shallow hearth; Exposure to the vacuum with coincident electron beam heating of the surface causes many volatile impurities and occluded gases to be drawn off of the molten material and thereby produces a greatly purified product.
  • containers which may be utilized in metal processing include tundishes, launders, and ladles for transferring molten material between various points. Electron beam heating may be utilized to maintain the material in a molten condition while in such containers.
  • vaporized material may present ionization problems or may coat the various parts of the electron beam gun, impairing its operation. Moreover, spalling of condensed materials from cool surfaces of the vacuum enclosure, and splashing and splattering of the molten material from the crucible, may also impair operation of the electron beam gun.
  • the heating of large surface areas in electron beam furnaces may be accomplished by employing a large number of electron beam guns with separate deflecting fields for each of the beams. If the furnace enclosure is relatively large, this may present no significant problem. However, if space is at a premium, the positioning of means for establishing transverse magnetic fields closely adjacent each other may be extremely difficult due to mutual interference and distortion of the fields. j
  • pole pieces or other means for producing a transverse magnetic field for deflecting an electron beam are positioned off to one side of the region above the molten target, the condensation problem mentioned above is lessened. Nevertheless, several factors limit the distance from the target material at which the deflecting means can be positioned. With too low an angle of incidence of the electron beam onto the target, surface structures adjacent the sides of the target surface, such as magnetic shields or structural members, may block the path of the beam. in addition, with a very low angle of incidence, the impact area on the surface of the target is spread out, resulting in a more inefficient transfer of heat.
  • Another object of the invention is to provide an improved heating system for use in an electron beam furnace in which efficient use is made of space and power.
  • Another object of the invention is to provide an electron beam furnace heating system of minimal complexity in which a plurality of electron beams may be directed and controlled through a curving path to a target.
  • FIG. 1 is a full section side view schematically illustrating a heating system constructed in accordance with the invention
  • FIG. 2 is a view taken along the line 22 of FIG. 1;
  • FIGS. 3 and 4 are plan views of alternate configurations for pole pieces in the heating system of FIGS. 1 and 2.
  • the electron beam furnace heating system of the invention comprises an electron beam gun 11 for producing an electron beam.
  • Means 12 are provided for directing the beam to a target 13.
  • the directing means include a pair of barshaped pole pieces 14 and 15 having their longitudinal axesin a common plane and positioned to produce a transverse magnetic field in the path of the beam.
  • Means 16 are provided for energizing the pole pieces to produce a magnetic field of sufficient strength that the electron beam is deflected to emerge from the same side of the magnetic field as the side from which it enters. The field is also of sufficient strength to prevent the electron beam from penetrating past a plane extending through the longitudinal axes of the pole pieces.
  • the electron beam furnace includes an evacuated enclosure, part of which is shown at 20.
  • the molten material target 13 is contained in an elongated container 17 which is cooled by circulating coolant in passages 18 to form a layer or skull 19 of solidified material between the molten material and the container walls.
  • the container 17 is illustrated as a hearth into which molten metal flows from a launder 21 (FIG. 2) at one end. The contents of the hearth are discharged at the other end through an opening 22 (FIG. 2), and the level of molten material in the hearth may be controlled by a weir, not shown.
  • molten material in the hearth and removing it therefrom may include such things as tundishes, siphons, or ladles. Between entry and exit, the'material flows slowly along the hearth and thereby has a very high exposure rate to the vacuum environment in which the illustrated apparatus is disposed.
  • the hearth type of arrangement illustrated provides a large surface area of molten material with shallow depth for long times of exposure of the molten material to the vacuum.
  • Such an arrangement is particularly useful in the purification of many types of steel and nickel base alloys as well as most of the refractory metals, such as columbium, tantalum, titanium, zirconium and others.
  • many purification reactions that involve differential vaporization phenomena or other types of outgassing require residence times of many tens of seconds with the molten surface exposed to very low pressures.
  • the illustrated configuration that of a long linear hearth with the molten material flowing slowly along it, is particularly advantageous.
  • Electron beams are utilized to prevent solidification of the material on the hearth as the material flows along the hearth, and to provide localized regions of high heat to vaporize impurities and produce thermal stirring.
  • a plurality of electron beams are utilized to provide heating of the target molten material 13 in the hearth 17.
  • the electron beams are produced by a plurality of similar electron beam guns, only one of which (11) is shown, distributed along and underneath the hearth 17 at spaced intervals.
  • the electron beam guns may be of any suitable type. A preferred form, however, is that shown and described in U.S. Pat. No. 3,514,656 assigned to the assignee of the present invention. The details of such a gun are shown in connection with the gun I! in FIG. 1. It is to be understood that the other guns may be of identical construction.
  • the electron beam gun 11 includes an elongated emitter 23 for producing electrons.
  • the emitter is preferably a tungsten wire and extends between the supporting membersv 24 and 25. Means, not illustrated, provide a direct current potential across the members 24 and 25, resulting in a flow of direct current through the emitter 23. The current flow raises the temperature of the emitter causing it to produce free electrons.
  • the freeelectrons produced by the emitter 23 are reflected on three sides by a shaping electrode 26.
  • the electrode 26 is insulated from the emitter support members 24 and 25 by insulating strips 27 and 28, respectively.
  • the shaping electrode 26 is formed with an elongated recess 29 through which the emitter 23 extends. When the shaping electrode is maintained at the emitter potential, by suitable connection not illustrated, the electrons produced bythe emitter 23 tend to move out of the open end of the recess 29 and away from the shaping electrode 26.
  • the electrons leaving the recess 29 in the shaping electrode 26 are accelerated into a beam by an accelerating electrode 31 and pass through an opening 32 therein.
  • the accelerating electrode 31 consists of a plate with two right angle extensions 33 and 34 thereon which are attached to suitable mounting means, not illustrated.
  • the plate 31 is maintained at a potential which is substantially more positive than the potential of the emitter and-the backing electrode to produce an acceleration of the electrons.
  • the result is a ribbon beam, that is, an electron beam having an elongated cross section which is ideally a narrowv rectangle but which approximates a narrow oval.
  • the beam has a major axis plane which extends through the emitter.
  • the electrons in the beam leave the emitter 23 at an acute angle in the major axis plane.
  • the axis of the beam is indicated by the dash-dot line 36, which represents the center of the ribbon beam.
  • a non-normal orientation of the initial electron path with respect to the emitter 23 is caused by the high intensity circumferential field produced by d-c heating current passing through the emitter.
  • the electron beam 36 is deflected about 90 through a curved path by means of a transverse magnetic field.
  • the transverse magnetic field is established in the initial path of the beam between a pair of elongated bar-shaped pole pieces 37, only one of which is illustrated.
  • the pole pieces extend generally parallel with the emitter 23 and each other and are positioned on either side of the 'beam 36 parallel with its major axis plane.
  • a magnet 38 extends between the upper ends of the pole pieces 37, and a magnet 39 extends between the lower ends of the pole pieces 37.
  • the two magnets are identically oriented with regard to their polarities, and are electromagnets connected to a suitable control circuit and power supply, not shown. The polarities are established with field lines running perpendicularly into the plane of the paper as illustrated in the drawing, thereby causing an upward deflection of the electron beam 36 as illustrated.
  • a vapor barrier 42 After leaving the electron beam gun l1 and after being deflected upwardly through a change in direction of about the electron beam is passed through an opening 4] in a vapor barrier 42.
  • the vapor barrier 42 may not always be necessary, in situations where a large quantity of vaporous material is produced, the vapor barrier 42 provides additional protection for the electron beam .gun 11.
  • a separate pumping system (not shown) may be provided in the lower region of the furnace interior to thereby maintain the electron beam gun I] in a substantially vapor-free environment. This enhances the life of the emitter of the electron beam gun and improves the quality of the beam as it enters the upper part of the furnace chamber.
  • the pole pieces 14 and 15 are provided. Similar pairs of pole pieces 44, 45 and 46, 47 are provided for deflecting the electron beams produced by the other guns, as may be seen in FIG. 2.
  • the electron beam is deflected back down onto the molten material in the hearth at an angle which is'preferably between about 30 and 60 from the vertical.
  • An angle greater than 60 with respect to the vertical generally results in a beam spot which is too spread out and, in addition, the beam may be interfered with by structures along the sides of the hearth.
  • An incident angle of less than 30 with respect to the vertical may necessitate the positioning of the pole piecestoo close to the region directly above the hearth, where the tendency for condensate to collect on the pole pieces is undesirably high.
  • the pole pieces 14 and 15 are energized to provide a magnetic field which extends transversely of the electron beam above the opening 41 through which the beam emerges and passes upwardly into the upper part of the electron beam furnace chamber.
  • the field includes a portion of substantially uniform strength in the region directly between the pole pieces.
  • the field also includes upper and lower fringe regions where the lines of flux flow outwardly away from the uniform region, and which diminish in strength with distance from the uniform region. For the purposes of the present invention, the upper fringe region may be ignored, as only the lower fringe region influences the electron beam or beams.
  • the pole pieces are positioned at such an'angle that the magnetic field established thereby deflects the beam back downwardly and over toward the target material 13.
  • the magnetic field between the slanted bar-shaped pole pieces is made sufficiently strong by the energizing means 16 so that the beam does not penetrate an appreciable distance into the region directly between the pole pieces, but rather is deflected through a change in direction of roughly entirely or nearly entirely within the fringe region of the field and emerges from the magnetic field on the same side as the side from which it entered.
  • the field established by the pole pieces functions in a manner similar to an optical mirror.
  • the lines of force of the magnetic field may be seen extending between the pole pieces 14 and 15.
  • the deflection of the electrons in theelectron beam takes place almost entirely within the curving or fringe portion of the magnetic field established below the region directly between the pole pieces.
  • a focusing action in the plane of the curving beam path may occur.
  • the focusing action may be so strong as to produce a sort of nodal point with subsequent difon the electron beam also produces a convergence of the op- 75 fusion of the beam.
  • the pole pieces 14 and 15 are supported on a pair of pole piece extensions 51 and 52, respectively.
  • the pole piece extensions are of a ferromagnetic material and have their ends opposite the pole pieces 14 and 15 in contact with the ends of the magnetic core 53 of an energizing coil 54.
  • the energizing coil is energized by suitable current from the energizing means.
  • the position and the shape of the pole pieces can be varied, depending upon the particular furnace geometry, to achieve the desired beam spot size and deflection characteristics. Condensate build-up may be easily compensated for by slight adjustment in the field strength when required.
  • the actual distance of the pole pieces from the target and from the electron beam source is dictated by'consideration of the desired impact angle of the beam and by the geometric spacing of the target and the gun.
  • the depth of the pole pieces does not have a substantial affect on beam trajectory, since the beam does not penetrate through the region between the pole pieces.
  • the size of the facing areas of the pole pieces determines the power needed to produce the required field strength.
  • the required field strength depends on the gun power as well as the amount of deflection desired.
  • the angle of the poles with respect to the horizontal depends upon the angle between the incoming electron beam path and the desired outgoing beam angle.
  • a plane p including the longitudinal axes of the poles is about perpendicular to a plane which bisects the angle formed by the incoming and outgoing beam paths and which is perpendicular to a plane therethrough.
  • a shield 60 of ferromagnetic material prevents the field adjacent the coil 54 and pole piece extensions 51 and 52 from affecting the beam.
  • the directing means include a suitable set of pole pieces 61 for providing orthogonal deflection of the electron beam as it passes just above the opening 41.
  • the deflection means 61 comprise four solenoidal type electromagnetic coils arranged with their axes intersecting and defining a rectangular planar region. The coils have cores of low magnetic reluctance which are in contact at each end to the cores of the immediately adjacent coils. Variation in the energization of the coils produces a change in the direction of the lines of force of the field established by the coils and therefore a change in the amount of deflection of the beam.
  • the depth at which the electron beam penetrates the region directly between the pole pieces is limited to that depth which would avoid undue limitation of the amount of beam sweep which is possible. Moreover, excessive penetration may result in the beam becoming to diflicult to control. Accordingly, the strength of the magnetic field is selected to avoid penetration of the beam past a plane extending between the longitudinal axes of the two pole pieces.
  • the configuration of the pole pieces 14 and 15 may be varied so that portions thereof are slanted inwardly toward each other. This may be accomplished either by using additional dipoles 63 as shown in FIG. 3, or by making the pole pieces themselves of appropriate configuration as shown in FIG. 4. By the use of this type of design, a more uniform field strength may be achieved since there may be less of a tendency for field strength to fall off toward the ends of the pole pieces because of their increasing proximity.
  • spurious field is established between the adjacent pole pieces of adjacent pairs.
  • a spurious field is established between the pole pieces 15 and 44 and between the pole pieces 45 and 46. Because deflection of the beam takes place almost completely in the fringe region of each main field, the fringes of the spurious fields thus established are out of the path of the electron beams, even at wide sweep angles. Thus, even though spurious fields are established between adjacent pole pieces in adjacent pairs, they produce no detrimental affect on the operation of the system.
  • Another advantage of the present system is that, if additional power is needed, a separate and redundant system may be placed on the opposite side of the hearth, thereby doubling the power for heating. Moreover, if desired, two electron beam guns may utilize the same pair of pole pieces for deflection, as is shown in connection with the pole pieces 46, 47 at the far right-hand edge of FIG. 2.
  • the invention provides an improved heating system in an electron beam furnace.
  • the invention is particularly useful in connection with a plurality of electron beams where a relatively large surface area is to be heated and where the beams are to be swept over the surface area.
  • the invention enables the pole pieces for establishing deflecting magnetic fields to be placed closely adjacent each other without adverse affect on the operation of the system.
  • the system is simple and reliable of operation.
  • a heating system comprising, an electron beam gun for producing an electron beam, and means for directing the beam to a target, said directing means including a pair of bar-shaped pole pieces having their longitudinal axes in a common plane and positioned to produce a transverse magnetic field in the path of the beam, said magnetic field having a region between said pole pieces of substantially straight lines of force and having a fringe region of bowed lines of force toward the direction from which the electron beam enters said magnetic field, means for varying the angle at which the electron beam is injected into the said magnetic field produced by said pole pieces to thereby vary the direction of the emerging beam, and means for energizing said pole pieces to produce a magnetic field of sufficient strength that the electron beam is deflected to emerge from the same side of said magnetic field as the side from which it enters, and is prevented from penetrating past a plane extending through the longitudinal axes of said pole pieces, said pole pieces being of a width such that substantially all of the electron beam is deflected within the fringe
  • a system according to claim 1 wherein said energizing means are adapted to provide a field strength sufficient to cause a change in direction of the beam through an angle of between about 105 and about 165.
  • each of said pole pieces is disposed to slant inwardly toward the corresponding portion of the other of said pole pieces such that the space between said pole pieces narrows in the direction of the region directly above the target.
  • said energizing means include an electromagnetic coil having a low reluctance core, means forming a low reluctance magnetic flux path from the ends of said core to the respective pole pieces, and a magnetic shield disposed between said coil and the path of the electron beam.
  • said path forming means include a pair of upright extensions of low reluctance material forming a flux path from the ends of said core to ends of the respective pole pieces, and wherein said magnetic shield is disposed between at least a portion of said extensions and the path of the electron beam.
  • a system according to claim 1 including a further electron beam gun positioned to project an electron beam into said magnetic field on the same side thereof as the beam produced by said first named electron beam gun, said energizing means being adapted to produce a magnetic field of sufficient strength that the electron beam produced by said further electron beam gun is deflected to emerge from the same side of the magnetic field as the side from which it enters and is prevented from penetrating past a plane extending through the longitudinal axes of said pole pieces.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Toxicology (AREA)
  • Health & Medical Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Electron Sources, Ion Sources (AREA)
US81720A 1970-10-19 1970-10-19 Heating system for electron beam furnace Expired - Lifetime US3655902A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US8172070A 1970-10-19 1970-10-19

Publications (1)

Publication Number Publication Date
US3655902A true US3655902A (en) 1972-04-11

Family

ID=22165960

Family Applications (1)

Application Number Title Priority Date Filing Date
US81720A Expired - Lifetime US3655902A (en) 1970-10-19 1970-10-19 Heating system for electron beam furnace

Country Status (7)

Country Link
US (1) US3655902A (enExample)
CA (1) CA923980A (enExample)
DE (1) DE2152094A1 (enExample)
FR (1) FR2111692A1 (enExample)
GB (1) GB1315480A (enExample)
IT (1) IT940886B (enExample)
SE (1) SE380159B (enExample)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3931490A (en) * 1973-09-17 1976-01-06 Robert Bosch G.M.B.H. Electron beam vaporization apparatus
US4038484A (en) * 1976-06-21 1977-07-26 Airco, Inc. Electron beam heating system
US4048462A (en) * 1975-01-17 1977-09-13 Airco, Inc. Compact rotary evaporation source
US4131753A (en) * 1977-05-18 1978-12-26 Airco, Inc. Multiple electron-beam vapor source assembly
US4599869A (en) * 1984-03-12 1986-07-15 Ozin Geoffrey A Cryogenic deposition of catalysts
US20200049140A1 (en) * 2010-10-07 2020-02-13 Vanderbilt University Peristaltic micropump and related systems and methods

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4891821A (en) * 1989-03-27 1990-01-02 Hanks Charles W Magnetic correcting fence for adjacent e-guns
DE3929475A1 (de) * 1989-09-05 1991-03-14 Balzers Hochvakuum Verfahren und vorrichtung zur umlenkung eines strahls

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2777958A (en) * 1951-02-10 1957-01-15 Hartford Nat Bank & Trust Co Magnetic electron lens
US3270233A (en) * 1961-09-05 1966-08-30 Heraeus Gmbh W C Plural beam electron gun
US3475542A (en) * 1967-09-13 1969-10-28 Air Reduction Apparatus for heating a target in an electron beam furnace

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2777958A (en) * 1951-02-10 1957-01-15 Hartford Nat Bank & Trust Co Magnetic electron lens
US3270233A (en) * 1961-09-05 1966-08-30 Heraeus Gmbh W C Plural beam electron gun
US3475542A (en) * 1967-09-13 1969-10-28 Air Reduction Apparatus for heating a target in an electron beam furnace

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3931490A (en) * 1973-09-17 1976-01-06 Robert Bosch G.M.B.H. Electron beam vaporization apparatus
US4048462A (en) * 1975-01-17 1977-09-13 Airco, Inc. Compact rotary evaporation source
US4038484A (en) * 1976-06-21 1977-07-26 Airco, Inc. Electron beam heating system
US4131753A (en) * 1977-05-18 1978-12-26 Airco, Inc. Multiple electron-beam vapor source assembly
US4599869A (en) * 1984-03-12 1986-07-15 Ozin Geoffrey A Cryogenic deposition of catalysts
US20200049140A1 (en) * 2010-10-07 2020-02-13 Vanderbilt University Peristaltic micropump and related systems and methods
US10781809B2 (en) * 2010-10-07 2020-09-22 Vanderbilt University Peristaltic micropump and related systems and methods

Also Published As

Publication number Publication date
FR2111692A1 (enExample) 1972-06-09
GB1315480A (en) 1973-05-02
SE380159B (enExample) 1975-10-27
DE2152094A1 (de) 1972-04-20
CA923980A (en) 1973-04-03
IT940886B (it) 1973-02-20

Similar Documents

Publication Publication Date Title
US3710072A (en) Vapor source assembly
US4687939A (en) Method and apparatus for forming film by ion beam
US3896258A (en) Electron beam gun system
US3432335A (en) Cyclically moving electron beam for uniform vapor deposited coating
US3655902A (en) Heating system for electron beam furnace
US3235647A (en) Electron bombardment heating with adjustable impact pattern
US3514656A (en) Electron beam gun assembly for producing a ribbon shaped beam and magnet means for transversely deflecting the beam about its major axis
US3068309A (en) Electron beam furnace with multiple field guidance of electrons
US5418348A (en) Electron beam source assembly
US3101515A (en) Electron beam furnace with magnetically guided axial and transverse beams
US3622679A (en) Heating system for electron beam furnace
US3177535A (en) Electron beam furnace with low beam source
US3394217A (en) Method and apparatus for controlling plural electron beams
US4131753A (en) Multiple electron-beam vapor source assembly
US3814829A (en) Device for electron-beam heating of materials mainly for their melting and evaporation
US3535428A (en) Apparatus for producing and directing an electron beam
US3883679A (en) Vapor source assembly
US3592955A (en) Electron beam furnace
US3409729A (en) Electron beam furnace and method for heating a target therein
US3446934A (en) Electron beam heating apparatus
US4724796A (en) Vaporization arrangement with a rectangular vaporization crucible and several electron guns
US3475542A (en) Apparatus for heating a target in an electron beam furnace
JPH04231458A (ja) 電子ビーム蒸発源
US3170019A (en) Electron beam furnace
US3483417A (en) Electron beam deflecting means