US3406273A - Magnetic vapor deflector for an electron beam - Google Patents

Magnetic vapor deflector for an electron beam Download PDF

Info

Publication number
US3406273A
US3406273A US601773A US60177366A US3406273A US 3406273 A US3406273 A US 3406273A US 601773 A US601773 A US 601773A US 60177366 A US60177366 A US 60177366A US 3406273 A US3406273 A US 3406273A
Authority
US
United States
Prior art keywords
line
electron beam
magnetic
materials
gap
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
US601773A
Other languages
English (en)
Inventor
Robert C Holland
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.)
RTX Corp
Original Assignee
United Aircraft Corp
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 United Aircraft Corp filed Critical United Aircraft Corp
Priority to US601773A priority Critical patent/US3406273A/en
Priority to CH1727667A priority patent/CH468077A/de
Priority to DE19671615473 priority patent/DE1615473A1/de
Priority to FR1549697D priority patent/FR1549697A/fr
Application granted granted Critical
Publication of US3406273A publication Critical patent/US3406273A/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
    • H01J37/02—Details
    • H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement
    • H01J37/147—Arrangements for directing or deflecting the discharge along a desired path
    • 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
    • H01J37/3002—Details
    • 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
    • H01J37/3002—Details
    • H01J37/3007—Electron or ion-optical systems

Definitions

  • This invention relates to a device for the protection of anelectron gun. More specifically it relates to a device for magnetically. deecting an electron beam about a structure interposed between the beam generating source and theworkpiecerat which the electron beam is directed.
  • the vapors emanating from a workpiece worked by an electron beam travel in essentially straight lines it is desirable to deflect the beam about a structure interposed between the electron source and the workpiece. With such arrangement, the damaging leffect of the vapors on the electron source is reduced since the vapors tend to deposit on the interposing structure and cannot reach the electron source.
  • 'lfhis invention offers a versatile, low cost magnetic deflection system for eliminating the straight line of sight path between the workpiece and an electron beam source.
  • single deflection coil for bending the electron beam a specific angle of is used.
  • a complicated electrical deflection' circuit is required to hold the beam on the desired ⁇ spot on the workpiece. Any ripple or instability of the deflection signal or of the accelerating voltage will produce undesired movement of the electron beam.
  • the circuit for the deecting coil Lcan respond fast to -beam accelerating voltage changes, the electron beam will be deflected whenever any transient condition occurs.
  • a major disadvantage to these' prior art beam bending devices is the cost and complication of the necessary electronic controls. I
  • the line of sight between the electron gun source and the workpiece is eliminated by using three permanent magnets to deflect the beam away from its original axis around a vapor deector 'and then back again along the original axis.
  • the first magnetic field produces a deflection angle of 0, the second magnet bends the beam back towards the axis with an angle of -20 and the third magnet bends the beam with an angle of 0 along the axis of the beam.
  • FIGURE 1 is a sectional view of a first embodiment of my invention.
  • FIGURE 2 is a view of the magnetic path through the magnetic bending device of the first embodiment.
  • FIGURE 3 is a side view of the first embodiment.
  • FIGURE 4 is a second embodiment of my invention.
  • the electron beam is a usefultool for the working of materials, for instance, in cutting, drilling or Welding of metals in a vacuum.
  • Such electron beam apparatus are well known in the art and one that may be used in connection with this invention is described in the patent to Steigerwald, 2,987,610.
  • the working of materials in a vacuum with an intense electron beam is usually accompanied by vaporization of the materials that are being worked. Such evaporation will cause damage to the cathode from which the electrons are produced if they are permitted to reach the cathode region.
  • Various schemes have been proposed to reduce the vapor flow to the cathode region, see, for instance, the patent to Opitz et al., 2,944,172.
  • FIGURE 2 there is shown a cathode 10 for generating a beam of electrons and a control electrode 12 and agrounded anode 14 for producing an accelerating field for the electrons generated by the cathode.
  • the electron beam 16 is focussed and then made to pass through a magnetic deflection device 18.
  • the magnetic deflector 18 consists of two oppositely facing E-shaped magnetic structures having three gaps 20, 22 and 24.
  • the magnetic field is produced by permanent magnets although it is, of course, possible to provide the magnetic field with the proper magnetization current from coils mounted on the E cores.
  • the cores are E-shaped but also have a third dimensional profile as is shown in the side view of FIGURE 3.
  • the gaps 20, 22 and 24 -between the pole faces ordinarily provide an unobstructed passage for the vapors emanating from the workpiece below the magnetic structure 18, and therefore a vapor deflector 26 is mounted las shown.
  • This deflector can take any shape desired as long as it interrupts the line of sight from the cathode 10 to the workpiece 28.
  • the vapor deflector 26 may even partially extend within the gap 22 but will then have to be of such material that it does not interfere with the magnetic flux within this gap.
  • the vapor deflector 26 also may be so shaped to substantially close off the vacuum chambe-r within which the magnetic structure 18 is mounted.
  • the vapor deflector When the vapor deflector is so shaped, only gap 22 provides a free passageway for the electron beam 16 to reach the workpiece 28 and by placing the pumping system 11 for ⁇ evacuating the chamber in which the cathode control electrode is located between the magnetic structure 18 and the work-piece, the amount of vapor entering the cathode region will be substantially reduced. It is also desirable to render the vapor deflector 26 conductive on the side facing the electron beam so that any stray electrons that may strike the Avapor deflector will not cause an undesirable accumulation of charge and avoid undesirable deflections.
  • FIGURE 3 a side view of the magnetic structure 18 shows how the deflector 26 interrupts the line of sight between the electron beam source and the workpiece and shows three different paths 30, 32 and 34 which the electron beam may take to pass around the vapor deflector. These three paths indicate the different bending angles of the electron beam as a result of variations in the accelerating potential.
  • the angle of defection 0 caused by a magnetic field is proportional to the accelerating voltage by the formula Patented Oct. l5, 1968 ⁇
  • the ,range of beam potential over which the device will operate is limited to a range over which is kept to excursions within the range of inuence of the gaps. If the beam potential did not stay within a given design range, the second gap could be missed by the beam and cause serious damage to the machine structure.
  • the three pole faces must be matched so that starting from the -point at which the electron beam enters the structure 18, the beam is defiected 0 degrees at the gap 20 and degrees at gap 22 and again +0 degrees at gap 24. r1 ⁇ he total resultant beam deiiection is zero and the advantage of this device is that it is independent of the variations in the beam potential.
  • the electron beam is deflected along a path vas is indicated by 30.
  • the beam will follow the path 32 and with the lowest beam potential it is deflected along path 34.
  • FIGURE 2 The flux pat-hs generated in the magnetic structure 18 are shown in FIGURE 2.
  • angu- FIGURE 4 shows an electron beam 16 entering a tube- 40.
  • the tube is made of such material that it passes the magnetic field of the magnet 42 and is positioned in the gap 44 of the magnet 42.
  • the magnetic field generated by the magnet 42 causes a deflection of the electron beam towards the slot 46 cut into tube 40. Thereby the electron beam passes through the slot 46 and enters the magnetic field generated by the magnet 48.
  • Magnet 48 has a gap 50 through which the electron beam 16 passes when it emerges from the slot 46.
  • the tube 40 extends also through the gap 50 to below the magnet 48 and is closed at the end facing the workpiece 28. It thus can be seen that if the magnetic field of magnets 42 and 48 are oriented in opposite directions to cause defiection of the beam 16 in opposite directions, the
  • beam 16 travels towards the workpiece along an axis parallel to the original line but offset therefrom at some distance depending upon the magnlitude of the field strength in the magnets and their size. It is of course possible to replace the permanent magnets 42 and 48 with magnets excited by a D.C. current through a coil wound on a magnetic core.
  • FIG- URE 4 eliminates a direct line of sight path for the vapors emanating from the workpiece area to the cathode 10.
  • the slot 46 is 4made sufficiently large to accommodate deiiection angle differences caused by variations in the accelerating potential of the electron beam.
  • Apparatus for working materials with a beam of charged particles comprising:
  • a vapor deflector interposed acrossv the first line between the beam generating means and the materials
  • the magnetic poles across the, tippergap nearest the beam generating means defiect the beam in a first direction away from the first line and past the vapor deflector
  • the vapor deector is positioned to mask the first line ybetween the upper and lower gaps and shield the beam generating means from vapors traveling from the materials along the rst line.
  • Apparatus for working materials with a beam of charged particles comprising: v
  • ⁇ a vapor deflector tube positioned to partially enclose the first line and having a closed end facing the materials and an open end facing the beam generating means
  • the tube being provided with an opening along its side
  • a first magnetic deiiector having its poles positioned adjacent the tube for detiecting the beam away from ⁇ the first line towards the side opening in the tube
  • a second magnetic deflector having its poles positioned near the side opening to defiect the -beam ina direction 'substantially parallel to the first line.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Particle Accelerators (AREA)
  • Welding Or Cutting Using Electron Beams (AREA)
US601773A 1966-12-14 1966-12-14 Magnetic vapor deflector for an electron beam Expired - Lifetime US3406273A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US601773A US3406273A (en) 1966-12-14 1966-12-14 Magnetic vapor deflector for an electron beam
CH1727667A CH468077A (de) 1966-12-14 1967-12-08 Vorrichtung zur Bearbeitung von Werkstücken mit einem Strahl geladener Partikel
DE19671615473 DE1615473A1 (de) 1966-12-14 1967-12-09 Vorrichtung zur Bearbeitung von Werkstuecken mit einem Strahl geladener Partikel
FR1549697D FR1549697A (de) 1966-12-14 1967-12-12

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US601773A US3406273A (en) 1966-12-14 1966-12-14 Magnetic vapor deflector for an electron beam

Publications (1)

Publication Number Publication Date
US3406273A true US3406273A (en) 1968-10-15

Family

ID=24408709

Family Applications (1)

Application Number Title Priority Date Filing Date
US601773A Expired - Lifetime US3406273A (en) 1966-12-14 1966-12-14 Magnetic vapor deflector for an electron beam

Country Status (4)

Country Link
US (1) US3406273A (de)
CH (1) CH468077A (de)
DE (1) DE1615473A1 (de)
FR (1) FR1549697A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3474220A (en) * 1967-05-17 1969-10-21 Webb James E Device for preventing high voltage arcing in electron beam welding
US3701922A (en) * 1970-08-31 1972-10-31 Northrop Corp Electron beam line scanner with transverse binary control
WO1996007195A1 (de) * 1994-08-27 1996-03-07 Linotype-Hell Ag Elektronenstrahl-erzeuger
US20100148086A1 (en) * 2007-05-15 2010-06-17 Ho Seob Kim Magnetic deflector for an electron column

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3474220A (en) * 1967-05-17 1969-10-21 Webb James E Device for preventing high voltage arcing in electron beam welding
US3701922A (en) * 1970-08-31 1972-10-31 Northrop Corp Electron beam line scanner with transverse binary control
WO1996007195A1 (de) * 1994-08-27 1996-03-07 Linotype-Hell Ag Elektronenstrahl-erzeuger
US5866974A (en) * 1994-08-27 1999-02-02 Linotype-Hell Ag Electron beam generator with magnetic cathode-protection unit
US20100148086A1 (en) * 2007-05-15 2010-06-17 Ho Seob Kim Magnetic deflector for an electron column
US8071955B2 (en) * 2007-05-15 2011-12-06 Cebt Co. Ltd. Magnetic deflector for an electron column

Also Published As

Publication number Publication date
CH468077A (de) 1969-01-31
DE1615473A1 (de) 1970-06-25
FR1549697A (de) 1968-12-13

Similar Documents

Publication Publication Date Title
Wåhlin The colutron, a zero deflection isotope separator
US7034297B2 (en) Method and system for use in the monitoring of samples with a charged particle beam
US2853641A (en) Electron beam and wave energy interaction device
US3777211A (en) Adjusting device for a particle beam
US2828434A (en) Electron beam focussing device
US3406273A (en) Magnetic vapor deflector for an electron beam
US20170004950A1 (en) X-ray generator and adjustment method therefor
US2214729A (en) Magnetic field neutralizing system
US7411192B2 (en) Focused ion beam apparatus and focused ion beam irradiation method
GB1246152A (en) Magnetic deflection apparatus
US3814829A (en) Device for electron-beam heating of materials mainly for their melting and evaporation
JPH01319236A (ja) 電界放射電子銃
US2909688A (en) Magnetic means for deflecting electron beams
US3469139A (en) Apparatus for electron beam control
US2886727A (en) Electron optical apparatus
US4180760A (en) Flat cathode ray tube having magnetically collimated electron beam device
US3869675A (en) Heating arrangement with focused electron beams under vacuum
US4160905A (en) Electron microscopes
US8653472B2 (en) Electromagnetic field application system
US3035203A (en) Cathode-ray tube
US4302704A (en) Postacceleration cathode ray tube with a scan expansion lens
JPH07233473A (ja) マグネトロンスパッタ装置
US3767927A (en) Electron beam apparatus with beam-stabilization system
US3302054A (en) Direct viewing storage tube having inclined flood gun and virtual cathode
US3226587A (en) Cathode ray tube and magnetic deflection means therefor