US3235647A - Electron bombardment heating with adjustable impact pattern - Google Patents
Electron bombardment heating with adjustable impact pattern Download PDFInfo
- Publication number
- US3235647A US3235647A US286063A US28606363A US3235647A US 3235647 A US3235647 A US 3235647A US 286063 A US286063 A US 286063A US 28606363 A US28606363 A US 28606363A US 3235647 A US3235647 A US 3235647A
- Authority
- US
- United States
- Prior art keywords
- pole pieces
- electrons
- lines
- crucible
- target
- 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
Links
- 238000010438 heat treatment Methods 0.000 title claims description 29
- 230000005291 magnetic effect Effects 0.000 claims description 89
- 239000013077 target material Substances 0.000 claims description 12
- 230000001939 inductive effect Effects 0.000 claims description 9
- 239000000463 material Substances 0.000 description 63
- 230000004907 flux Effects 0.000 description 58
- 238000000034 method Methods 0.000 description 28
- 238000010894 electron beam technology Methods 0.000 description 19
- 239000012768 molten material Substances 0.000 description 9
- 230000001419 dependent effect Effects 0.000 description 8
- 230000008569 process Effects 0.000 description 7
- 238000007493 shaping process Methods 0.000 description 6
- 239000007787 solid Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 238000004804 winding Methods 0.000 description 4
- 239000002131 composite material Substances 0.000 description 3
- 230000001976 improved effect Effects 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 239000013014 purified material Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000005574 cross-species transmission Effects 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000010408 sweeping Methods 0.000 description 2
- 240000005369 Alstonia scholaris Species 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000005674 electromagnetic induction Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000003550 marker Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000005293 physical law Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 230000008093 supporting effect Effects 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
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
- C22B9/04—Refining by applying a vacuum
-
- 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
- the present invention relates generally to electron bombardment heating as variously employed in highvacuum furnaces to treat material in the conduct of casting operations, vapor coating processes, metal purification processes, and the like.
- the invention is more particularly directed to an improvement in the magnetic guidance of electron beams to facilitate substantial variation in the pattern of bombarding electrons at impact with the material to be heated.
- Electron bombardment heating is extensively employed in high-vacuum furnaces as a mechanism for treating material undergoing various processes therein. More particularly, these high-vacuum furnaces typically include an enclosure which is continuously evacuated to a high vacuum. Material melted within the enclosure becomes highly purified inasmuch as any volatile impurities, occluded gases, and the like evolved from the material during the melting thereof is withdrawn by the continuous evacuation of the enclosure. The melted material is in some instances streamed into a cold mold wherein the material is further heated at the open top of the mold to maintain a molten pool of material within the mold atop a solidifying ingot therein. The ingot is of highly-purified material and may be continuously withdrawn from the lower portion of the mold.
- the material may be melted and maintained molten within a crucible and subsequently cast therefrom into a mold disposed within the vacuum enclosure to form a casting of highly-purified material.
- vapors evolved from the molten material within a crucible are deposited upon a surface as a plated layer or coating of the material in highly-purified form. Irrespective of the specific arrangement of components within the vacuum enclosure, or the specific processes conducted therein, heating of the material to melt same and/or maintain same molten in the high-vacuum surroundings is most effectively accomplished by bombardment of the material with electrons.
- the bombarding electrons are generated by one or more electron guns, each including an electron-emissive cathode and accelerating anode structure for directing the electrons evolved from the cathode upon the crucible, mold, or other desired target, as an electron beam.
- the electron velocity, and therefore energy, of the beam may be readily controlled commensurate with a desired extent of heating of the material at the particular target.
- an electron gun is typically disposed at a remote location relative to the crucible, or other target, and a magnetic field is generated in space with regions of the field disposed adjacent the gun and target.
- the magnetic lines of force may be established generally parallel to the target surface, and electrons are directed from the gun into the magnetic field transversely to the lines of force.
- the magnetic field deflects the electrons along curved trajectories to the target with the pattern of impact of the electrons thereon being determined by the characteristics of the magnetic field.
- impact pattern requirements may vary considerably depending upon the nature of the particular target to be "ice bombarded, as Well as other conditions prevailing Within the high-vacuum enclosure.
- the magnetic field characteristics should be such as to defiect the electrons into a substantially circular impact pattern which uniformly covers the top of the crucible without substantial spillover of the beam.
- three electron guns might, for example, be employed in the bombardment of a circular target, such as the open top of a cylindrical crucible.
- the impact pattern of each beam is a 120-degree sector of the circular target area, or triangle having an apex angle of 120 degrees. With these circular sectors or triangles circumferentially adjacent each other at the target surface area, it will be appreciated that efiicient overall coverage thereof is obtained.
- a beam impact pattern having a given desired configuration such as those just mentioned, it has been necessary to tailor the magnetic guidance field to suit the particular situation.
- the present invention overcomes the foregoing disadvantages and limitations associated with previous methods of adjusting electron beam impact pattern by the provision of a method and means for generating magnetic guidance field whose characteristics are variable in such a manner that electrons may be thereby focused into substantially any desired impact pattern at a target. More particularly, the present invention provides for the generation of a magnetic guidance field by a plurality of pole pieces, or the like, which are magnetically coupled by a low-reluctance flux path interconnecting same. Provision is made for the controlled variation of flux densities in respective linking portions of the flux path between the various pole pieces to, in turn, facilitate separate adjustment of the densities of the lines of force adjacent the respective pole pieces.
- Separate coils magnetically linked with the linking portions of the flux path and means for separately controlling current flow through these coils may be, for example, employed to vary the flux densities in the respective linking portions.
- the lines of force extending between the pole pieces may be readily adjusted to have varied amounts of skewness or slant.
- the extent and direction of skewness of the magnetic lines of force determine the positions at which electrons directed into the field impact a target. Consequently, by varying the skewness, the points of electron impact at the target and thus the impact pattern is varied.
- a wide variety of impact pattern configurations are readily attainable through control of the magnetic field in the foregoing manner.
- continuous movement of the impact pattern over the target is herein effected by shifting maximum flux density alternately between linking portions of the flux path to thus alternate the direction of skewness of the magnetic lines of force.
- a relatively large target area may be covered by sweeping the impact pattern in this manner, provided of course that some nonuniformity in heating of the target surface with respect to time can be advantageously employed or at least tolerated. Sweeping of the impact pattern over the target surface in the foregoing manner may additionally be employed to facilitate thermal stirring of a pool of molten material in a crucible or the like, where same comprises the bombardment target area.
- FIGURE 1 is a vertical section through an electron beam vacuum furnace embodying improve-d electron beam magnetic guidance apparatus in accordance with the present invention
- FIGURE 2 is a fragmentary sectional View taken at line 22 of FIGURE 1,
- FIGURE 3 is a schematic illustration of improved magnetic guidance apparatus in accordance with the invention depicting magnetic lines of force thereby generated, as viewed in rear elevation,
- FIGURE 4 is a schematic illustration of the guidance apparatus depicting magnetic lines of force produced thereby as viewed in plan
- FIGURE 5 is a perspective view, partially in schematic of an alternative form of magnetic guidance apparatus in accordance with the invention.
- FIGURE 6 is a schematic illustration of the apparatus of FIGURE 5, as viewed in end elevation, depicting magnetic lines of force skewed in accordance with the method of the invention, and
- FIGURE 7 is a view similar to FIGURE 6, but depicting magnetic lines of force skewed in the opposite direction in accordance with the method.
- FIGURE 1 Considering first one type of electron beam high-vacuum furnace in general, and referring to FIGURE 1, there will be seen to be illustrated an enclosure 11 defining a chamber 12 communicated with evacuation means 13 for continuously pumping the chamber in order to maintain a high vacuum therein.
- a container into which material such as metal may be deposited.
- such container is provided as a crucible 14 formed of copper, or the like, with passages 16 therein for circulation of a coolant to maintain the walls of the crucible at a nondestructive relatively low temperature compared to that of material within the crucible heated to a molten condition.
- the crucible 14 is movable between an upright position wherein material to be heated may be introduced to the open top of the crucible through a seal lock 17 or the like provided in the top of enclosure 11 in overlying relation to the crucible, and a downwardlypivoted pouring position wherein molten material in the crucible is cast into a mold 118 or the like appropriately positioned at the base of the enclosure. Controlled tilting of the crucible is facilitated in a manner analogous to that disclosed in a copending application for U.S. Letters Patent of Hugh R. Smith, Jr., Serial No.
- the crucible being mounted upon a platform 19 with stub shafts 21 journalled in the walls of enclosure 11 with at least one crank 22 employed in association with one of the shafts 21 and coupled to a remotely-controllable pushbar linkage 23.
- a pneumaticallyoperated piston or the like (not shown), coupled to the linkage 23, same may be retracted or extended to thereby pivot the crucible between its upright material receiving, and tilted pouring positions.
- the particular illustration of the crucible 14 herein as being tiltable and employed in relation to the mold 13 to cast molten material therein is purely exemplary and that the crucible may as well be fixed and employed for other purposes, such as in the vapor deposition of molten material contained therein upon an appropriately disposed overlying surface.
- the container for material referred to hereinbefore in its broad connotation is to be taken as including, in addition to crucibles, cold molds of a type into which molten material is continuously streamed from solid melt stock undergoing heating and melting within the chamber 12, with the material solidifying in the lower portions of the cold mold and supporting a molten pool at the upper end thereof whereby the solidified portion may be continuously withdrawn from the mold in the form of an ingot of highly-purified material.
- Heating of material within the vacuum chamber 12 to initially melt same, and maintain same molten in various phases of any desired process being conducted therein is advantageously accomplished by electron bombardment heating.
- one or more electron guns are provided to direct electron beams upon the material being processed at the various process stations thereof.
- one or more electron guns are provided to direct electron beams into the open top of the crucible to initially melt and/or maintain the material therein molten.
- material within molds or other containers are frequently maintained molten by electron bombardment heating, while in other instances bombarding electron beams are directed upon the material as introduced to the chamber in the form of solid melt stock, to initially melt same and effect continuous streaming thereof into a cold mold or other container.
- the term target is herein employed to designate the surface of the material upon which the electrons are directed.
- the target is the exposed surface, as generally indicated at 24, of material held within the open-topped cylindrical crucible 14.
- electrons are directed upon the surface 24 from a single electron gun 26 which, for example, may be structurally provided and operated as disclosed in my prior application for U.S. Letters Patent, Serial No. 37,615, filed June 21, 1961, now Patent No. 3,177,535.
- the gun is advantageously, although not necessarily, disposed forwardly of the crucible and downwardly from the open top thereof.
- contamination of the electrode structure 27 thereof by deposition of vapors rising from the molten ma terial within the crucible is greatly minimized.
- the gun 26 in the instant embodiment is provided integrally with the crucible 14, such gun being mounted upon bracket structure 28 carried by the crucible.
- the gun and crucible are tiltable as a unit in a manner analogous to that provided by the tiltable crucible arrangement of the hereinbefore-referenced copending patent application Serial No. 221,807.
- this magnetic field generating means includes a pair of parallel-spaced pole pieces 29, 31, respectively disposed on opposite sides of the crucible 14.
- pole pieces are advantageously -of substantially flat vertically elongated rectangular configuration having their upper ends extending above the open top of the crucible and their vertical side edges respectively adjacent an intermediate region of the crucible and a location forwardly of the electrode structure 27 of the gun 26.
- a forward portion of the crucible and the electrode structure of the electron gun are disposed within a spatial region transversely defined between the pole pieces 29, 31.
- means are provided to connect the lower ends of the pole pieces through a low-reluctance flux path, and preferably such means comprises a substantially U-shaped yoke 32 of high-permeability material such as soft iron.
- Such yoke includes a transverse web portion 33 extending between the lower ends of upright parallel leg portions 34, 36 respectively secured in magnetically-coupled relation to the base edges of pole pieces 29, 31.
- the entire pole piece and yoke assembly is secured to the crucible 14, as by means of a bracket 37 extending transversely between the pole pieces and peripherally secured to the forward portion of the crucible 14.
- the yoke 32 links magnetic winding means for inducing magnetic flux within the yoke.
- a closed magnetic circuit is of course defined by the yoke and pole pieces and the air space extending transversely between the latter.
- lines of magnetic force extend substantially transversely between the pole pieces and are distributed in a spatial region later-ally and upwardly adjacent the electrode structure 27 of gun 26 and the forward portion of the crucible 14.
- the lines of force adjacent the vertical side edges of the pole pieces are of generally convex configuration projecting outwardly from the pole piece edges.
- These convex lines of force constitute fringe regions of the magnetic field diposed at longitudinally opposite ends of a substantially uniform central field region wherein the lines of force are generally linear and more closely spaced.
- the magnetic field strength in the region of the fringing fields is less than that in the central region of the field and the electrode structure 27 of the electron gun is disposed in one fringing field, whereas the target surface 24 at the top of the crucible is disposed in the other fringing field.
- electrons emitted from the electrode structure 27 enter a fringing field transversely to the lines of force and are deflected along curved trajectories extending through the central field region of relatively high field strength and then through the other fringing field into the top of the crucible 14.
- the electrons are focused to form an impact pattern at the target surface 24 substantially covering same as indicated by envelope 38 of the focused electron beam.
- the impact pattern at the target surface 24 is not circular to conform to the configuration of the target surface comensurate with optimum efliciency of beam utilization. Instead, the impact pattern includes opposed drawn-in portions such that the impact pattern configuration substantially resembles that of a keyhole.
- the beam impact pattern in order to obtain complete cover-age of the target surface 24, the beam impact pattern must be sufficiently enlarged that the minor dimension thereof between the opposed drawn-in portions is as great as the diameter of the circular target area.
- the method hereof may be employed in the foregoing situation to control the held between pole pieces 29, Eli in such a manner as to produce a circular impact pattern conforming to the top of crucible 14.
- a variable impact guidance method is employed, which may be applied in various ways in a high-vacuum furnace to facilitate bombardment heating of material therein with the foregoing advantages irrespective of the particular form of the material and the specific stage of processing which it undergoes.
- the material may the in the form of a solid ingot of melt stock continuously introduced to the furnace for subjection to heating at its leading end, to melt the material and stream same into a cold mold, crucible or the like.
- the material may be molten and contained within a crucible, cold mold or the like.
- the method of the invention applies equally as well in any case.
- a magnetic guidance field is generated in the vicinity of a target represented by material to be treated in whatever form (i.e. solid melt stock, molten material held within a container or the like) as disposed within the high-vacuum region of a vacuum furnace.
- a low-reluctance flux path interconnecting a plurality of pole pieces adjacent the target.
- Magnetic flux is then induced in the flux path to establish the magnetic field, lines of force of the field extending between the pole pieces and hence occupying a region of space adjacent the target.
- the electrons are then directed into the field transverse to the flux lines thereof between the pole pieces for focusing upon the material representing the target.
- the flux densities in portions of the flux path linking respective ones of the pole pieces are controllably, separately varied to skew or slant the directions .of the lines of force extending between the pole pieces. It has been found that through such controlled variation of the degree and direction of skewness of the field lines, substantially any desired impact pattern at the target of electrons directed transversely into the field may be produced.
- this step of the method preferably consists in separately and cont-rollably inducing flux in the respective linking portions of the flux path in controlled proportions commensurate with the observation of an impact pattern having a desired configuration.
- This Step of the method may be somewhat modified if desired to provide a swept impact pattern.
- magnetic flux may be induced alternately in respective ones of the linking portions of the flux path or the flux may be alternately reversed in direction in one linking portion to thereby alternately skew the lines of force of the magnetic field in opposite directions and accordingly effect continuous movement and variation in the configuration of the impact pattern of the electrons upon the target.
- thermal agitation or stirring of the material representing the target being bombarded is produced, which effect is sometimes highly desirable.
- the method of the invention likewise applies in situations where a target is bombarded by electrons from a plurality of distinctly separate focused directions, as opposed to a single direction.
- a plurality of low-reluctance flux paths each interconnecting a plurality of pole pieces, are established at equally circumferentially-spaced radii emanating from a point on the target.
- Magnetic flux is separately and controllably induced in respective linking portions between respective pole pieces associated with each of the plurality of fiux paths, to thereby establish magnetic fields having lines of force between the respective sets of pole pieces at angularly-spaced locations adjacent the target.
- Electrons are introduced to the respective magnetic fields transversely to the lines of force thereof for focusing upon the target from a plurality of angularly displaced directions.
- the flux densities in the respective linking portions of each flux path are then adjusted relative to each other, as by separately and controllably electromagnetically inducing flux in the respective linking portions, to provide a plurality of impact patterns of the electrons respectively focused from the plurality of angularly displaced directions.
- These impact patterns are angularly adjacent each other at the target and have configurations commensurate with the establishment of a composite impact pattern covering a predetermined area of the target.
- the target comprises material within an open-top cylindrical crucible and it is desired that the composite impact pattern cover the exposed surface of the material, in other words a circular surface area
- the flux densities in the respective linking portions of each flux path are adjusted such that the electrons focused thereby form sectorial or triangular impact patterns on the exposed surface of the material with slight overlaps between the respectively adjacent ones thereof.
- the composite pattern is substantially circular and efiiciently covers the exposed surface of the material.
- the method outlined hereinbefore possesses substantial varsatility in its application.
- the method embraces situations where the magnetic field is primarily included in a spatial region overlying a target such as the top of a crucible or the like, occupies a spatial region laterally adjacent the material to be treated, or has various other spatial dispositions relative to the target material to be treated.
- the electrons may be introduced to the field in any of its conceivable spatial dispositions from positions above, below, laterally of, etc., the target to be bombarded.
- FIGURES 1 and 2 wherein the magnetic guidance field is established between pole pieces 29, 31 in a spatial region overlying crucible 14 and extending forwardly and downwardly from the top thereof, and wherein the electrons are directed from gun 26 into the field from a location forwardly and downwardly from the top of the crucible.
- controlled variation of the skewness of the magnetic lines of force is facilitated by adjustment of the relative flux densities in opposite sides of a low-reluctance fiux path defined by the yoke 32, connecting the pole pieces 29, 31.
- the opposite sides or legs 34, 36 of the yoke define the linking portions of the flux path mentioned hereinbefore relative to the method. More particularly, where the flux density in leg 34 of the yoke is made greater than that flowing in leg 36, the lines of force extending between the pole pieces 29, 31 are skewed, or slanted, in the direction of the pole piece 29 associated with the leg portion 34 of greatest flux density. Conversely, when the leg 36 has a greater density of flux than the leg 34, the lines of force between the pole pieces are skewed in the opposite direction towards pole piece 31 associated with the leg 36 of greatest flux density. Moreover, when the fiux densities in legs 34, 36 are equal, the lines of force between the pole pieces 29, 31 are substantially parallel to the web portion 33 of the yoke and accordingly possess substantially zero skewness.
- Variation of the relative flux densities between the respective legs of the flux path is preferably facilitated by means of a pair of coils 37, 38 magnetically linked with separate legs. More particularly, coils 37, 38 may be advantageously concentrically disposed about core portions of the legs 34, 36 at the lower ends thereof adjacent the web 33 of the yoke. These coils are separately energized by power supplies 39, 41 appropriately connected to the coils such that upon energization, flux is induced in the respective legs of the yoke in additive directions. The densities of the flux induced in the respective legs is of course dependent upon the magnitudes of the currents separately applied to the coils.
- the relative proportions of the flux densities in the respective legs of the yoke may be correspondingly varied over a wide range to skew the lines of force between the pole pieces by substantially any desired amount in either direction.
- the controlled skewing of the magnetic lines of force between the pole pieces in accordance with the present invention occurs principally in transverse planes extending longitudinally of the pole pieces.
- skewing of the field lines primarily occurs in transverse vertical planes between the pole pieces, as depicted in FIGURE 3. Skewing of the field lines to a lesser extent may also occur in transverse planes normal to the aforementioned transverse planes, that is in horizontal transverse planes between the pole pieces.
- the leg portions of the yoke are secured to the pole pieces at the vertical side edges thereof which are disposed adjacent the intermediate region of the crucible 14.
- the pole pieces accordingly include sections which project forwardly from the legs of the yoke.
- skewing of the field lines in horizontal transverse planes between the pole pieces may be effected, which skewing could not be provided were the legs of the yoke to be secured to the midpoints of the pole pieces rather than to one side thereof.
- the coils 37, 38 may be alternately energized by power supplies 39, 41.
- the flux densities in the respective legs 34, 36 of the yoke are thereby alternately maximized to skew the field lines alternately in opposite directions and thus sweep the impact pattern.
- pole pieces 29, 31 of the preferred apparatus of the invention may be provided as solid plates, same are more advantageously formed of a plurality of vertically-elongated, longitudinally-spaced bar segments 46. More specifically, the bar segments are fabricated of high-permeability material and are secured at their lower ends to a cross member 47 of the same material. The cross members 47 are in turn attached to the leg portions 34, 36 of the yoke 32. With the pole pieces thus provided in segmented form, a magnetic field may still be established between the pole pieces which is substantially similar to that established by solid pole pieces. However, by providing the pole pieces in the form of the spaced bar segments 46, the pole pieces may be more effectively cooled by virtue of the air spaces existing between the bar segments.
- the spaced-apart pole piece segments present minimized obstruction to the evacuation of the volume between the pole pieces.
- this improved evacuation of the space between the pole pieces is highly desirable inasmuch as copious amounts of molecules, ions and the like are evolved to this spatial region from the molten material within the crucible or the like.
- the trajectories of bombarding electrons moving through the guidance field are detrimentally effected by collision processes occurring between the electrons and gaseous material, and the impact pattern of the electrons at the target surface may be undesirably distorted.
- the amount of gaseous matter within the space between the pole pieces is materially minimized by virtue of the more effective evacuation of same through the spaces between the pole piece segments and as a result the undesirable effects of electron collisions are greatly obviated.
- the method of the invention may be alternatively conducted with the modified apparatus for generating a selectively skewable field illustrated in FIGURE 5.
- a plurality of pole pieces 48, 49, 51 are provided instead of the pair of pole pieces of the apparatus of FIGURES 1-4.
- Pole pieces 48, 49 are disposed in opposed transversely spaced relation, while pole piece 51 is disposed in spaced-parallel relation to pole piece 48 in a common longitudinal plane therewith.
- a yoke 52 of high permeability material is secured to the pole pieces to define a low reluctance flux path interconnecting same. More particularly, the yoke includes a web 53 interconnecting parallel legs 54, 56 projecting from the opposite ends thereof.
- leg 54, 56 are, in turn, respectively secured at their free ends to the pole pieces 48, 51 at corresponding ends thereof and adjacent their outer longitudinal edges.
- the web 53 is secured to pole piece 49 in planar relation thereto, the pole piece projecting longitudinally from the web adjacent leg 54 at the opposite end of this leg from pole piece 48.
- leg 54 defines a linking portion of the yoke flux path between pole pieces 48, 49.
- Leg 56, with web 53 defines a linking portion of the flux path between pole pieces 49, 5-1.
- legs 54, 56, together with web 53 define a linking portion of the yoke flux path between pole pieces 48 and 51.
- a pair of coils 57, 58 are preferably concentrically disposed about the legs 54, 56. These coils are separately and controllably energized, as by means of variable direct current power supplies 59, 61 connected thereto.
- variable direct current power supplies 59, 61 connected thereto.
- the lines of force between the magnetic field established between the pole pieces is substantially as indicated by the dashed lines of FIGURE 6.
- the magnetic lines of force are skewed downwardly towards the right (as viewed in FIGURE 6) in a region 62 of the space between the pole pieces, adjacent pole piece 49. The amount of skewing is, of course, dependent upon the relative magnitudes of the currents flowing in the coils 57, 58.
- An electron beam furnace comprising an enclosure, 7
- a yoke of high permeability material including a web with parallel legs projecting from its opposite ends, said legs respectively secured at their free ends to said second and third pole pieces, said web secured to said first pole piece, a pair of coils respectively linking said legs to establish upon energization a magnetic field having lines of force extending between said pole pieces, means disposed ad jacent said pole pieces for directing electrons into said magnetic field transversely to said lines of force, and power supply means coupled to said coils for controllably separately energizing same to adjust the impact pattern of said electrons upon said material and control the heating thereof,
- An electron beam furnace for controllably heating the surface of a target material disposed therein comprising, an enclosure, means for evacuating said enclosure, an electron gun disposed within said enclosure for generating a high intensity beam of electrons, means for establishing a unitary transverse magnetic field in the path of said beam of electrons, said unitary magnetic field establishing means including at least one pole piece on each side of said electron gun and a low-reluctance yoke interconnecting said pole pieces, and means for selectively inducing a variable magnetic flux in said pole pieces so as to provide magnetic lines of force of controllable direction of orientation extending between said pole pieces for focusing said beam of electrons upon the surface of said target material.
- An electron beam furnace for controllably heating the surface of a target material disposed therein comprising, an enclosure, means for evacuating said enclosure, an electric gun disposed within said enclosure for generating a high intensity beam of electrons, means for establishing a unitary transverse magnetic field in the path of said beam of electrons, said unitary magnetic field establishing means including parallel-spaced pole pieces disposed on opposite sides of said electron gun, a low-reluctance yoke interconnecting said pole pieces, and magnetic windings magnetically coupled to said pole pieces for inducing magnetic flux therein, and means for selectively energizing said windings so as to provide magnetic lines of force of controllably, variable direction of orientation extending between said pole pieces, said direction of orientation of said lines of force being dependent upon the differential energization supplied to said windings, whereby the surface of said target material is controllably heated.
- An electron beam furnace for controllably heating the surface of a target material comprising, an enclosure, means for evacuating said enclosure, an open-top container disposed within said enclosure for holding the target material, means for establishing a unitary transverse magnetic field above the open top of said container, said unitary magnetic field establishing means including at least one pair of parallel-spaced pole pieces disposed on opposite sides of said container, said pole pieces extending outwardly from the open top of said container and forwardly of a peripheral portion thereof, a low reluctance yoke interconnecting said pair of pole pieces, and coils magnetically coupled to said pole pieces for inducing magnetic flux therein, power supply means for selectively energizing said coils so as to establish magnetic lines of force of controllable direction of orientation dependent upon the differential energization supplied to said coils by said power supply means extending between said pole pieces, and an electron gun having a straight cathode disposed at one side of said container and extending in the same general direction as said lines of force for injecting a
- An electron beam furnace for controllably heating the surface of a target material comprising, an enclosure, means for evacuating said enclosure, a crucible disposed within said enclosure for holding the material to be heated, means for establishing a unitary transverse magnetic field above the surface of said crucible, said unitary magnetic field establishing means including at least one pair of parallel-spaced pole pieces disposed on opposite sides of said crucible, said pole pieces extending outwardly from the open top of said crucible, and extending forwardly from an intermediate region thereof to a position beyond the periphery of said crucible, a yoke of high permeability material interconnecting said pair of pole pieces, and a pair of coils magnetically coupled to said pole pieces for inducing magnetic flux therein, a pair of D.-C.
- An electron beam furnace for controllably heating the surface of a target material disposed therein comprising, an enclosure means for evacuating said enclosure, an electron gun disposed within said enclosure for generating a high intensity beam of electrons, means for establishing a unitary transverse magnetic field in the path of said beam of electrons, said unitary magnetic field establishing means including at least one pair of parallel spaced pole pieces disposed on opposite sides of said electron gun, each of said pole pieces comprising a plurality of parallel-spaced-apart pole piece segments so as to facilitate the evacuation of the region between said pole pieces, and a low reluctance yoke interconnecting said pole pieces, and means for selectively inducing a variable magnetic flux in said pole pieces so as to establish magnetic lines of force of controllable direction of orientation extending between said pole pieces for focusing said beam upon said material.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Plasma & Fusion (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Electron Sources, Ion Sources (AREA)
- Physical Vapour Deposition (AREA)
Priority Applications (12)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US286063A US3235647A (en) | 1963-06-06 | 1963-06-06 | Electron bombardment heating with adjustable impact pattern |
LU46219D LU46219A1 (de) | 1963-06-06 | 1964-06-01 | |
FR976891A FR1405965A (fr) | 1963-06-06 | 1964-06-03 | Chauffage par bombardement électronique avec impact réglable |
NO153507A NO117490B (de) | 1963-06-06 | 1964-06-03 | |
GB23048/64A GB1039135A (en) | 1963-06-06 | 1964-06-03 | Improvements in or relating to heating by electron bombardment |
DET26314A DE1185820B (de) | 1963-06-06 | 1964-06-05 | Verfahren zur Erhitzung von Materialien durch Elektronenbeschuss |
SE6903/64A SE317454B (de) | 1963-06-06 | 1964-06-05 | |
BR159794/64A BR6459794D0 (pt) | 1963-06-06 | 1964-06-05 | Aquecimento por bombardeio eletronico com padrao de impacto aprestavel |
BE648897A BE648897A (de) | 1963-06-06 | 1964-06-05 | |
NL6406393A NL6406393A (de) | 1963-06-06 | 1964-06-05 | |
DK284164AA DK122700B (da) | 1963-06-06 | 1964-06-06 | Fremgangsmåde til opvarmning af et smelteligt materiale ved elektronbombardement og elektronstråleovn til brug ved udøvelse af fremgangsmåden. |
CH739864A CH441539A (de) | 1963-06-06 | 1964-06-06 | Verfahren und Ofen zum Erhitzen von Material durch Elektronenbeschiessung |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US286063A US3235647A (en) | 1963-06-06 | 1963-06-06 | Electron bombardment heating with adjustable impact pattern |
Publications (1)
Publication Number | Publication Date |
---|---|
US3235647A true US3235647A (en) | 1966-02-15 |
Family
ID=23096903
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US286063A Expired - Lifetime US3235647A (en) | 1963-06-06 | 1963-06-06 | Electron bombardment heating with adjustable impact pattern |
Country Status (11)
Country | Link |
---|---|
US (1) | US3235647A (de) |
BE (1) | BE648897A (de) |
BR (1) | BR6459794D0 (de) |
CH (1) | CH441539A (de) |
DE (1) | DE1185820B (de) |
DK (1) | DK122700B (de) |
GB (1) | GB1039135A (de) |
LU (1) | LU46219A1 (de) |
NL (1) | NL6406393A (de) |
NO (1) | NO117490B (de) |
SE (1) | SE317454B (de) |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3397672A (en) * | 1965-11-10 | 1968-08-20 | United States Steel Corp | Control system for vapor-deposition coating apparatus |
US3446934A (en) * | 1968-01-30 | 1969-05-27 | Air Reduction | Electron beam heating apparatus |
US3474218A (en) * | 1966-01-10 | 1969-10-21 | Air Reduction | Electron beam conditioning ingot and slab surfaces |
US3483417A (en) * | 1967-07-26 | 1969-12-09 | Air Reduction | Electron beam deflecting means |
US3514656A (en) * | 1966-12-16 | 1970-05-26 | Air Reduction | Electron beam gun assembly for producing a ribbon shaped beam and magnet means for transversely deflecting the beam about its major axis |
US3554512A (en) * | 1969-03-24 | 1971-01-12 | George H Elliott | Crucible for holding molten semiconductor materials |
DE1790115B1 (de) * | 1967-09-13 | 1971-07-15 | Air Reduction | Vorrichtung zur erwaermung eines in einem elektrone nstrahlofen enthaltenen zielobjekts |
US3710072A (en) * | 1971-05-10 | 1973-01-09 | Airco Inc | Vapor source assembly |
US4488902A (en) * | 1983-06-10 | 1984-12-18 | Duval Corporation | Horizontal, multistage electron beam refinement of metals with recycle |
WO1984004933A1 (en) * | 1983-06-10 | 1984-12-20 | Duval Corp | Electron beam refinement of metals, particularly copper |
US4516525A (en) * | 1982-10-28 | 1985-05-14 | International Business Machines Corporation | Electron gun equipment for vacuum deposition |
US4983806A (en) * | 1990-03-01 | 1991-01-08 | Harper James L | Method and device for cooling electron beam gun |
US5111022A (en) * | 1989-08-23 | 1992-05-05 | Tfi Telemark | Cooling system for electron beam gun and method |
US20100021624A1 (en) * | 1999-12-27 | 2010-01-28 | Semiconductor Energy Laboratory Co., Ltd | Film Formation Apparatus and Method for Forming a Film |
US8815331B2 (en) | 2000-05-02 | 2014-08-26 | Semiconductor Energy Laboratory Co., Ltd. | Film-forming apparatus, method of cleaning the same, and method of manufacturing a light-emitting device |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3390222A (en) * | 1965-08-17 | 1968-06-25 | Air Reduction | Electron beam apparatus with variable orientation of transverse deflecting field |
GB9521517D0 (en) * | 1995-10-20 | 1995-12-20 | P A Dyson Limited | Gas burning device |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US571463A (en) * | 1896-11-17 | Controlling electric arcs | ||
US2572600A (en) * | 1947-01-17 | 1951-10-23 | Arthur J Dempster | Mass spectrograph |
US2719924A (en) * | 1945-12-28 | 1955-10-04 | Oppenheimer J Robert | Magnetic shims |
US2941077A (en) * | 1958-07-07 | 1960-06-14 | Applied Radiation Corp | Method of enlarging and shaping charged particle beams |
US3046936A (en) * | 1958-06-04 | 1962-07-31 | Nat Res Corp | Improvement in vacuum coating apparatus comprising an ion trap for the electron gun thereof |
US3068309A (en) * | 1960-06-22 | 1962-12-11 | Stauffer Chemical Co | Electron beam furnace with multiple field guidance of electrons |
-
1963
- 1963-06-06 US US286063A patent/US3235647A/en not_active Expired - Lifetime
-
1964
- 1964-06-01 LU LU46219D patent/LU46219A1/xx unknown
- 1964-06-03 GB GB23048/64A patent/GB1039135A/en not_active Expired
- 1964-06-03 NO NO153507A patent/NO117490B/no unknown
- 1964-06-05 SE SE6903/64A patent/SE317454B/xx unknown
- 1964-06-05 DE DET26314A patent/DE1185820B/de active Pending
- 1964-06-05 BR BR159794/64A patent/BR6459794D0/pt unknown
- 1964-06-05 NL NL6406393A patent/NL6406393A/xx unknown
- 1964-06-05 BE BE648897A patent/BE648897A/xx unknown
- 1964-06-06 DK DK284164AA patent/DK122700B/da unknown
- 1964-06-06 CH CH739864A patent/CH441539A/de unknown
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US571463A (en) * | 1896-11-17 | Controlling electric arcs | ||
US2719924A (en) * | 1945-12-28 | 1955-10-04 | Oppenheimer J Robert | Magnetic shims |
US2572600A (en) * | 1947-01-17 | 1951-10-23 | Arthur J Dempster | Mass spectrograph |
US3046936A (en) * | 1958-06-04 | 1962-07-31 | Nat Res Corp | Improvement in vacuum coating apparatus comprising an ion trap for the electron gun thereof |
US2941077A (en) * | 1958-07-07 | 1960-06-14 | Applied Radiation Corp | Method of enlarging and shaping charged particle beams |
US3068309A (en) * | 1960-06-22 | 1962-12-11 | Stauffer Chemical Co | Electron beam furnace with multiple field guidance of electrons |
Cited By (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3397672A (en) * | 1965-11-10 | 1968-08-20 | United States Steel Corp | Control system for vapor-deposition coating apparatus |
US3474218A (en) * | 1966-01-10 | 1969-10-21 | Air Reduction | Electron beam conditioning ingot and slab surfaces |
US3514656A (en) * | 1966-12-16 | 1970-05-26 | Air Reduction | Electron beam gun assembly for producing a ribbon shaped beam and magnet means for transversely deflecting the beam about its major axis |
US3483417A (en) * | 1967-07-26 | 1969-12-09 | Air Reduction | Electron beam deflecting means |
DE1790115B1 (de) * | 1967-09-13 | 1971-07-15 | Air Reduction | Vorrichtung zur erwaermung eines in einem elektrone nstrahlofen enthaltenen zielobjekts |
US3446934A (en) * | 1968-01-30 | 1969-05-27 | Air Reduction | Electron beam heating apparatus |
US3554512A (en) * | 1969-03-24 | 1971-01-12 | George H Elliott | Crucible for holding molten semiconductor materials |
US3710072A (en) * | 1971-05-10 | 1973-01-09 | Airco Inc | Vapor source assembly |
US4516525A (en) * | 1982-10-28 | 1985-05-14 | International Business Machines Corporation | Electron gun equipment for vacuum deposition |
US4488902A (en) * | 1983-06-10 | 1984-12-18 | Duval Corporation | Horizontal, multistage electron beam refinement of metals with recycle |
WO1984004933A1 (en) * | 1983-06-10 | 1984-12-20 | Duval Corp | Electron beam refinement of metals, particularly copper |
US4518418A (en) * | 1983-06-10 | 1985-05-21 | Duval Corporation | Electron beam refinement of metals, particularly copper |
US5111022A (en) * | 1989-08-23 | 1992-05-05 | Tfi Telemark | Cooling system for electron beam gun and method |
US4983806A (en) * | 1990-03-01 | 1991-01-08 | Harper James L | Method and device for cooling electron beam gun |
US20100021624A1 (en) * | 1999-12-27 | 2010-01-28 | Semiconductor Energy Laboratory Co., Ltd | Film Formation Apparatus and Method for Forming a Film |
US8968823B2 (en) | 1999-12-27 | 2015-03-03 | Semiconductor Energy Laboratory Co., Ltd. | Method of manufacturing a light emitting device |
US9559302B2 (en) | 1999-12-27 | 2017-01-31 | Semiconductor Energy Laboratory Co., Ltd. | Method of manufacturing a display device |
US8815331B2 (en) | 2000-05-02 | 2014-08-26 | Semiconductor Energy Laboratory Co., Ltd. | Film-forming apparatus, method of cleaning the same, and method of manufacturing a light-emitting device |
Also Published As
Publication number | Publication date |
---|---|
DK122700B (da) | 1972-03-27 |
CH441539A (de) | 1967-08-15 |
NO117490B (de) | 1969-08-18 |
GB1039135A (en) | 1966-08-17 |
SE317454B (de) | 1969-11-17 |
BE648897A (de) | 1964-10-01 |
DE1185820B (de) | 1965-01-21 |
LU46219A1 (de) | 1964-08-01 |
BR6459794D0 (pt) | 1973-12-26 |
NL6406393A (de) | 1964-12-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3235647A (en) | Electron bombardment heating with adjustable impact pattern | |
EP0495447B1 (de) | Verfahren zur Steuerung eines Lichtbogenpunktes beim Vacuumbeschichten mittels Lichtbogenentladung und eine Verdampfungsquelle | |
RU2544328C2 (ru) | Ионно-плазменные излучатели электронов для плавильной печи | |
JP5781710B2 (ja) | 鋳造又は噴霧されて粉末になる処理材料を製造する方法 | |
DE102010049521B3 (de) | Vorrichtung zum Erzeugen eines Elektronenstrahls | |
US3420977A (en) | Electron beam apparatus | |
US3896258A (en) | Electron beam gun system | |
JPH06128741A (ja) | 回転式陰極 | |
US3710072A (en) | Vapor source assembly | |
US3068309A (en) | Electron beam furnace with multiple field guidance of electrons | |
US3303320A (en) | Vapor-coating apparatus | |
US3132198A (en) | Electron beam furnace | |
US3101515A (en) | Electron beam furnace with magnetically guided axial and transverse beams | |
US3177535A (en) | Electron beam furnace with low beam source | |
JPH09104977A (ja) | 基板を被覆するための装置 | |
US3394217A (en) | Method and apparatus for controlling plural electron beams | |
US3265801A (en) | Electron beam furnaces | |
NO153507B (no) | Brannroer for rotasjonsprosjektil. | |
US3622679A (en) | Heating system for electron beam furnace | |
US3655902A (en) | Heating system for electron beam furnace | |
US3814829A (en) | Device for electron-beam heating of materials mainly for their melting and evaporation | |
US3526206A (en) | Coating apparatus including electron beam evaporating means | |
US3535428A (en) | Apparatus for producing and directing an electron beam | |
US3170019A (en) | Electron beam furnace | |
US3475542A (en) | Apparatus for heating a target in an electron beam furnace |