US2777958A - Magnetic electron lens - Google Patents

Magnetic electron lens Download PDF

Info

Publication number
US2777958A
US2777958A US266298A US26629852A US2777958A US 2777958 A US2777958 A US 2777958A US 266298 A US266298 A US 266298A US 26629852 A US26629852 A US 26629852A US 2777958 A US2777958 A US 2777958A
Authority
US
United States
Prior art keywords
lens
pole
electron
revolution
plane
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
US266298A
Other languages
English (en)
Inventor
Poole Jan Bart Le
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.)
Hartford National Bank and Trust Co
Original Assignee
Hartford National Bank and Trust Co
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 Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
Application granted granted Critical
Publication of US2777958A publication Critical patent/US2777958A/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
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/58—Arrangements for focusing or reflecting ray or beam
    • H01J29/64—Magnetic lenses
    • 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
    • H01J49/00—Particle spectrometers or separator tubes
    • H01J49/44—Energy spectrometers, e.g. alpha-, beta-spectrometers
    • H01J49/46—Static spectrometers

Definitions

  • a transverse field magnetic lens for electrons or other energized particles is characterised in that one of the two pole surfaces is a sector having an angle (lens angle) of not more than 270 of a plane of revolution and in that a plane at right angles to the axis of revolution, intersecting with one of the tangents of the generatrix of the plane of revolution under an angle of 30 or less at a distance from the axis of revolution which is equal to that of the tangent point, is the plane with respect to which the second pole surface is the reflection of the first pole surface or else forms the counterpole surface itself.
  • the counterpole surface is defined to mean a pole surface located either along the plane which is perpendicular to the axis of revolution or located to constitute a mirror image of the first pole surface with respect to that plane, the two surfaces defining the region through which the charged beam passes and is acted upon by the magnetic field existing between the two surfaces.
  • a lens of particular quality is obtained, if the generatrix of the plane of revolution forms part of a parabola, the apex of which lies in the axis of revolution. Each tangent of this curve intersects the equatorial plane at a point being equally spaced apart from the axis of revolution as the tangent point.
  • 21 parabola may be replaced by a tangent which gives the plane of revolution the shape of a conical surface.
  • the tangent which, as far as its inclination with respect to the equalatorial plane and its point of intersection with this plane are concerned, fulfills the aforesaid condition,
  • the optical axis of the lens according to the invention is a circle section, of which the center lies on the axis of revolution and of which the radius varies with the magnetic field strength and the velocity of the particles.
  • the size of this radius acts upon the astigmatism of the lens. It is in this case a minimum, if the spacing between the pole surfaces in the area of the optical axis is twice the spacing between their point of intersection with the axis of revolution (the cone tops).
  • the strength of the lens is determined, among other things, by the size of the lens angle. Suitable values for this angle to ensure a strong lens lie between 120 and 135. The maximum lens strength is obtained at an angle of 127% It is usually inefficient to energise a magnetic electron lens, of which the lines of force extend primarily in the direction of the electron paths (longitudinal field lens) by means of a permanent magnet. This would be useful, if the electrons should have a velocity which is materially lower than that usually employed in electron microscopes. Since the transverse field lens, owing to the focussing efiect, requires a materially smaller magneto-motive force, the energisation is effected here by permanent magnetism, even at considerably higher electron velocities. This implies a simplification of the construction (no energising current circuit, no cooling) and an economy in losses.
  • the optically operating field of the electron lens must be arranged in a vacuous space.
  • the energising winding of the radially symmetrical longitudinal field lens can be readily arranged outside the vacuous space, which is surrounded by the cylindrical yolre.
  • the shape of the transverse field lens is less suitable for a similar arrangement. lt'is easier to arrange this lens as a whole in the vacuous space.
  • the permanent magnet eliminates the disadvantage involved in the arrangement of an energising winding in the vacuous space.
  • the image produced by this lens shifts in place at a variation of the acceleration voltage.
  • This property of the transverse field lens may be utilised to scan the image; however, the same property involves a disadvantage, when the transverse field lens is used as an electron-optical system in an electron microscope, of which the working voltage is not sufficiently constant. This disadvantage may be mitigated by providing the microscope with a system of two or more transverse field lenses, which are traversed in succession by the electron beam and which deflect the latter in the same plane and in the same sense. These lenses may be arranged relative to one another and to the object in a manner such that the resultant image produced by the lens system does not exhibit any or substantially any chromatic shift.
  • the electron-optical lens system directs the electron beam on the mirror formed by the electrodes of the electron gun and reproducing on an amplified scale the image on which the beam thus directioned is focussed.
  • Fig. 1 serves to explain the focussing effect of a homogeneous magnetic field on electron paths.
  • Figure 2 shows a pole shoe of a transverse field lens viewed in the direction of the axis of revolution.
  • Fig. 3 is a cross sectional view of the transverse field lens, with which the pole shoe shown in Fig. 2 is associated, taken in the plane IIIIII of Fig. 2.
  • Fig. 3a is a perspective view of the transverse field lens shown in Fig. 3, together with a yoke.
  • Fig. 4 is a diagrammatical view of the arrangement of two transverse field lenses in an electron microscope according to the invention.
  • Fig. 4a is a cross sectional view of the diagrammatic arrangement shown in Fig. 4.
  • the cross-hatched part represents a homogeneous magnetic field, of which the lines of force are at right angles to the plane of the drawing.
  • Two electron paths 1 and 2 located in this plane, enter the field under an angle of to the boundary plane 3 of the magnetic field. In the field they are circularly curved by the Lorenz force and emerge from the field again as parallel lines.
  • the circle arcs intersect with one another at point 4. If the boundary plane 3 is not flat, but curved with the axis 18 at point 19.
  • pole surfaces between which the electron paths extend are not flat, but if they are shaped in the form of planes of revolution, in accordance with the invention, a non-homogeneous magnetic field is produced between these pole surfaces. If these pole surfaces extend over a sector of 270 or less, a beam of electrons may be tangentially introduced into this field. The field has a focussing effect on this beam both in an axial and a radial direction. There is thus produced a lens.
  • FIG. 2 designates a pole shoe of such a transverse field lens, viewed in the direction of the axis of revolution 6.
  • FIG. 3 shows the two pole shoes 5 and 7 in a sectional view in the flat plane IIlllI through the axis 6 of Fig. 2.
  • the sectional area of the pole surfaces 8 and 9 is a parabola, of which the top 10 lies on the axis 6.
  • the two pole shoes are made of ferromagnetic material and are associated with one magnetic system. They are interconnected by means of a yoke 41 (Fig. 3a.), which is surrounded by an energising winding or which includes a permanent magnet 42. If the system has a north pole at 7, the south pole is at 5. A non-homogeneous magnetic field prevails in the space between these poles, through which a beam of energised particles is passed.
  • a focussing which is generally sufficient for practical purposes may be obtained by replacing the parabolic sectional areas of the pole surfaces by straight lines 16 and 17 i. e. by rendering the pole surfaces conical.
  • the straight lines 16 and ll7 are tangents to the parabolic lines 8 and 9 at points 34 and 35.
  • the position of the optical axis i. e. the radius of the path in the equatorial plane, which is circularly curved,
  • the strength of the lens varies with the angle 0- between the end surfaces 20 and 21 of the pole shoes, which may be termed the lens angle.
  • the maximum lens strength is obtained, if this angle is 127%".
  • the focal distance of a transverse field lens having a lens angle of this maximum value is R x/Z where R designates the radius of the are, which is formed by the optical axis of the lens.
  • the maximum limit of 270 for the lens angle of the lens disclosed in this application is set, since with angles exceeding 270 it is not always possible to center the elec tron beam about the optical axis.
  • the property of an image producing lens, according to the invention, that at variation of the electron velocity, the image shifts in position, i. e. the chromatic displacement, is a disadvantage for an electron microscope provided with such a lens. If the lens should have a separating power of A., the relative variation of the working voltage may not exceed This requirement is severe and often difficult to fulfill. However, the chromatic displacement may be reduced and even completely obviated, if the electron beam emerging from the lens is collected in a second transverse field lens, which curves the electron beam in the same sense.
  • the chromatic displacement may be eliminated, at least as far as it is a lens error of the first order.
  • the chromatic displacement which is left as a lens error of higher order is so small that requirements for the constance of the working voltage and the magnetic field strength are less severe than with a longitudinal field lens having the same separating power. A relative variation of is permissible in many cases.
  • Figs 4 and 4a show an arrangement of two transverse field lenses for an electron microscope according to the invention. These figures also show diagrammatically the electron gun of the microscope. The latter is formed by a filament cathode 22, a Wehnelt cylinder 23 and an anode 24. The system formed by these electrodes emits a ray of electrons 25, if suitable voltages are applied thereto. This ray enters the transverse field lens 26 at right angles to one of the boundary surfaces designated 1 by 20 and 21 in Fig. 2; the ray is curved therein in a manner such that it emerges from this lens in the direction 27.
  • the axis of the electron ray coincides with the optical of the lens 26, which'may be ensured by a suitable choice of the voltage or of the magnetic field strength and a suitable arrangement of the lens.
  • This lens produces an amplified image at point 29 of a speciman arranged near the lens 26 at point 28.
  • This image constitutes in its turn the object for a second transverse field lens 30, in which the ray is again curved in the direction 31.
  • the lens 30 could be caused to produce an image on a collecting screen struck by the ray 31.
  • the microscope may be provided with a third electronoptical system, if this is required for the control of the amplification or for an increase in amplification.
  • the ray can be curved through a total angle of more than 180 by the two lenses 26 and 30 provides the possibility of arranging the lenses in a manner such that the ray of electrons 31, emerging from the lens 30, enters into the electro-static field of the electrode system 23, 24. From an electron-optical point of view this system then operates as a convex mirror. If the image plane of this lens 30 lies behind this mirror, for example, at 32, the mirror 23, 24 reproduces the image on an enlarged scale in a plane located, for example, at 33'(see Fig. 4a). By means of a collecting screen (fluorescent screen or photographic film) arranged in this plane this image may be rendered visible.
  • a collecting screen fluorescent screen or photographic film
  • the plane 32 (Fig. 4) indicates the plane in which an image would be formed if the mirror 23, 24 was not functioning. With respect to the mirror 23, 24, therefore, the imaginary image formed in the plane 32 may be regarded as the virtual object for producing the final image on the screen 33.
  • the ray 31 need not necessarily be exactly directed to the aperture of the anode 24 (Fig. 4), through which the electrons initially emerge.
  • a second aperture may be provided for the ray 31, behind which is located the electrode 23, which is at a low negative potential with respect to the electron source 22, when the microscope operates.
  • the electron ray may be given its correct course by suitable choice of the distance of the lens 26 from the electron gun and of the spacing between the lenses 26 and 30.
  • the ray emerging from the transverse field lens may be deflected in direction by varying the lens angle.
  • An efiicient distance between the lens 26 and the electron gun is 50 centimeters.
  • the spacing between the image plane 33 and the electrode system 23, 24 may be of the same order.
  • the radius of curvature R2 must be 21 mms., if it is assumed that the two lenses produce a sevenfold amplification.
  • the lenses 26 and 30 may be provided with a common yoke, so that a lens system is obtained which excells in simplicity and easy arrangement, particularly, if the lenses can be arranged closed to one another by choosing the sum of the two lens angles to be only slightly in excess of 180.
  • a magnetic lens for deflecting and focussing said beam on said viewing means comprising a pair of opposed spaced ferromagnetic pole members defining tw opposed mirror-symmetrical pole surfaces each being a surface of revolution formed by a generatrix approximating a part of a parabola the apex of which lies on the axis of revolution and shaped in the form of a sector of a circle having an angle of not less than and not more than 270, and a ferromagnetic yoke connecting said pole members and forming therewith a closed magnetic circuit including an air-gap between the polemembers.
  • a magnetic lens for deflecting and focussing said beam on said viewing means comprising a pair of opposed spaced ferromagnetic pole members defining two opposed mirror-symmetrical pole surfaces each being a conical surface of revolution formed by a generatrix which is a tangent to a parabola the apex of which lies on the axis of revolution and shaped in the form of a sector of a circle having an angle of not less than 90 and not more than 270, and a ferromagnetic yoke connecting said pole members and forming therewith a closed magnetic circuit including an air-gap between the pole-members.
  • a magnetic lens for deflecting and focussing said beam on said viewing means comprising a pair of opposed spaced ferromagnetic pole members defining two opposed mirror-symmetrical pole surfaces each being a conical surface of revolution formed by a generatrix which is a tangent to a parabola the apex of which lies on the axis of revolution and shaped in the form of a sector of a circle having an angle of not less than and not more than and a ferromagnetic yoke connecting said pole members and forming therewith a closed magnetic circuit including an air-gap between the polemembers.
  • a magnetic lens for deflecting and focussing said beam on said viewing means comprising a pair of opposed spaced ferromagnetic pole members defining two opposed mirror-symmetrical pole surfaces each being a conical surface of revolution formed by a generatrix which is a tangent to a parabola the apex of which lies on the axis of revolution and shaped in the form of a sector of a circle having an angle of about 127%. and a ferromagnetic yoke connecting said pole members and forming therewith a closed magnetic circuit including an air-gap between the pole-members.
  • a magnetic lens for deflecting and focussing said beam on said viewing means comprising a pair of opp sed. ,sp ed, ferro a net polemembersv defining two opposed mirron-symnietfical pole surfaces ;ea ch being. ,a conical sur face .of revolution formed by a generatrix which is a tangent to a parabola the apex of whichlies on thevaxis-of revolution and shaped inthe form of a sector of a circle having an angle of not, less. than 90 and not more than 270,.and a permanentflmagnetyoke connectingv said pole, membersv and forming ,therewith ,a closed magnetic'circuit including. an, air-gap between the pole-members.
  • a magnetic lensSYStem for. deflecting and focussing said beam on said viewing meanscomprising two pairs of opposed spaced ferromagnetic pole members successively positioned inthe pathof ,theelectron beam, each pair of pole members defining two Opposed mirrorsymmetrical pole surfaces eachbeing a surface of revolution formed by a generatrix approximating a part of a parabola the apex of which lieson the, axis of revolution and shaped in the form of a sector of a circle having an angle of not less than 90 and not more than 270, and a ferromagnetic yoke connecting said pole members and forming therewith a closed magnetic circuit including an air-gap between the pole-members.
  • a magneticlens SYSIQmiQrUdefleQting andfocussingusaidbeam on s i view ugzmeans comprising tw pairs of ppaomdsuace ferromagnetic lpole, members successively positioned in the pathoftheelectron beam, each pair oflpole members defining two opposed,mirror-symmetrical pole surfaces eachbeinga 'surfacelof revolutionformed by a generatrixapproximating apart of a parabola the apex of which lieson the ,axis of revolution and shaped in theform of a sector of a circle having an angle of, not less than 90 and, not more than 270", and aferromagnetic yoke connecting said pole, members andforming therewith a closed magnetic circuit including an air-gap between the polemembers, said respective pairs of

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Electron Tubes For Measurement (AREA)
  • Electron Beam Exposure (AREA)
US266298A 1951-02-10 1952-01-14 Magnetic electron lens Expired - Lifetime US2777958A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL302299X 1951-02-10

Publications (1)

Publication Number Publication Date
US2777958A true US2777958A (en) 1957-01-15

Family

ID=19783341

Family Applications (1)

Application Number Title Priority Date Filing Date
US266298A Expired - Lifetime US2777958A (en) 1951-02-10 1952-01-14 Magnetic electron lens

Country Status (6)

Country Link
US (1) US2777958A (fr)
BE (1) BE509097A (fr)
CH (1) CH302299A (fr)
DE (1) DE911878C (fr)
FR (1) FR1058851A (fr)
GB (1) GB753562A (fr)

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2872574A (en) * 1956-04-12 1959-02-03 Edwin M Mcmillan Cloverleaf cyclotron
US2909688A (en) * 1957-02-19 1959-10-20 Vickers Electrical Co Ltd Magnetic means for deflecting electron beams
US2926255A (en) * 1956-10-25 1960-02-23 Nat Res Dev Electron lenses
US2931903A (en) * 1957-06-17 1960-04-05 High Voltage Engineering Corp Acceleration and application of high intensity electron beams for radiation processing
US2939954A (en) * 1957-02-16 1960-06-07 Philips Corp X-ray shadow microscope
US3197678A (en) * 1961-09-26 1965-07-27 Trub Tauber & Co Ag Apparatus for producing magnetic fields
US3243667A (en) * 1962-04-09 1966-03-29 High Voltage Engineering Corp Non dispersive magnetic deflection apparatus and method
US3308293A (en) * 1963-04-24 1967-03-07 Ass Elect Ind Method of selectively separating charged particles using a variable intensity non-uniform magnetic field
US3360647A (en) * 1964-09-14 1967-12-26 Varian Associates Electron accelerator with specific deflecting magnet structure and x-ray target
US3379911A (en) * 1965-06-11 1968-04-23 High Voltage Engineering Corp Particle accelerator provided with an adjustable 270deg. non-dispersive magnetic charged-particle beam bender
US3516037A (en) * 1967-12-05 1970-06-02 High Voltage Engineering Corp Nondispersive magnetic deflection method
US3655902A (en) * 1970-10-19 1972-04-11 Air Reduction Heating system for electron beam furnace
US3659236A (en) * 1970-08-05 1972-04-25 Us Air Force Inhomogeneity variable magnetic field magnet
US3660658A (en) * 1969-03-12 1972-05-02 Thomson Csf Electron beam deflector system
US3671895A (en) * 1969-05-05 1972-06-20 Thomson Csf Graded field magnets
US3673528A (en) * 1971-03-01 1972-06-27 Gen Electric Wide frequency response line scan magnetic deflector
US3767927A (en) * 1970-08-28 1973-10-23 Philips Corp Electron beam apparatus with beam-stabilization system
US4281251A (en) * 1979-08-06 1981-07-28 Radiation Dynamics, Inc. Scanning beam deflection system and method
WO1988001731A1 (fr) * 1986-08-25 1988-03-10 Eclipse Ion Technology, Inc. Exploration parallele rapide par faisceaux ioniques ayant une lentille magnetique bipolaire avec champ non uniforme
US4922106A (en) * 1986-04-09 1990-05-01 Varian Associates, Inc. Ion beam scanning method and apparatus
US4980562A (en) * 1986-04-09 1990-12-25 Varian Associates, Inc. Method and apparatus for high efficiency scanning in an ion implanter
US5053627A (en) * 1990-03-01 1991-10-01 Ibis Technology Corporation Apparatus for ion implantation
US5279723A (en) * 1992-07-30 1994-01-18 As Represented By The United States Department Of Energy Filtered cathodic arc source
US5347254A (en) * 1993-03-08 1994-09-13 The United States Of America As Represented By The Secretary Of The Army Tubular structure having transverse magnetic field with gradient
WO1999017865A1 (fr) * 1997-10-07 1999-04-15 University Of Washington Separateur magnetique pour dispersion lineaire et procede de fabrication
US6661016B2 (en) 2000-06-22 2003-12-09 Proteros, Llc Ion implantation uniformity correction using beam current control
US20040084636A1 (en) * 2000-03-27 2004-05-06 Berrian Donald W. System and method for implanting a wafer with an ion beam

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2143579A (en) * 1934-12-20 1939-01-10 Ruska Ernst Combined deflecting device for cathode ray tubes
US2260041A (en) * 1939-03-22 1941-10-21 Gen Electric Electron microscope
US2272165A (en) * 1938-03-01 1942-02-03 Univ Leland Stanford Junior High frequency electrical apparatus
US2429558A (en) * 1945-08-24 1947-10-21 Research Corp Electron beam monochromator
US2435386A (en) * 1946-07-27 1948-02-03 Rca Corp Electron diffraction camera
US2447260A (en) * 1945-06-21 1948-08-17 Research Corp Electron microspectroscope
US2457495A (en) * 1944-12-18 1948-12-28 Sylvania Electric Prod Ultra high frequency tube
US2469964A (en) * 1941-05-03 1949-05-10 Bell Telephone Labor Inc Electron discharge apparatus
US2533687A (en) * 1949-05-27 1950-12-12 Quam Nichols Company Magnetic focusing device
US2551544A (en) * 1944-09-20 1951-05-01 Alfred O C Nicr Mass spectrometer
US2636999A (en) * 1953-04-28 x x x x i

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2636999A (en) * 1953-04-28 x x x x i
US2143579A (en) * 1934-12-20 1939-01-10 Ruska Ernst Combined deflecting device for cathode ray tubes
US2272165A (en) * 1938-03-01 1942-02-03 Univ Leland Stanford Junior High frequency electrical apparatus
US2260041A (en) * 1939-03-22 1941-10-21 Gen Electric Electron microscope
US2469964A (en) * 1941-05-03 1949-05-10 Bell Telephone Labor Inc Electron discharge apparatus
US2551544A (en) * 1944-09-20 1951-05-01 Alfred O C Nicr Mass spectrometer
US2457495A (en) * 1944-12-18 1948-12-28 Sylvania Electric Prod Ultra high frequency tube
US2447260A (en) * 1945-06-21 1948-08-17 Research Corp Electron microspectroscope
US2429558A (en) * 1945-08-24 1947-10-21 Research Corp Electron beam monochromator
US2435386A (en) * 1946-07-27 1948-02-03 Rca Corp Electron diffraction camera
US2533687A (en) * 1949-05-27 1950-12-12 Quam Nichols Company Magnetic focusing device

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2872574A (en) * 1956-04-12 1959-02-03 Edwin M Mcmillan Cloverleaf cyclotron
US2926255A (en) * 1956-10-25 1960-02-23 Nat Res Dev Electron lenses
US2939954A (en) * 1957-02-16 1960-06-07 Philips Corp X-ray shadow microscope
US2909688A (en) * 1957-02-19 1959-10-20 Vickers Electrical Co Ltd Magnetic means for deflecting electron beams
US2931903A (en) * 1957-06-17 1960-04-05 High Voltage Engineering Corp Acceleration and application of high intensity electron beams for radiation processing
US3197678A (en) * 1961-09-26 1965-07-27 Trub Tauber & Co Ag Apparatus for producing magnetic fields
US3243667A (en) * 1962-04-09 1966-03-29 High Voltage Engineering Corp Non dispersive magnetic deflection apparatus and method
US3308293A (en) * 1963-04-24 1967-03-07 Ass Elect Ind Method of selectively separating charged particles using a variable intensity non-uniform magnetic field
US3360647A (en) * 1964-09-14 1967-12-26 Varian Associates Electron accelerator with specific deflecting magnet structure and x-ray target
US3379911A (en) * 1965-06-11 1968-04-23 High Voltage Engineering Corp Particle accelerator provided with an adjustable 270deg. non-dispersive magnetic charged-particle beam bender
US3516037A (en) * 1967-12-05 1970-06-02 High Voltage Engineering Corp Nondispersive magnetic deflection method
US3660658A (en) * 1969-03-12 1972-05-02 Thomson Csf Electron beam deflector system
US3671895A (en) * 1969-05-05 1972-06-20 Thomson Csf Graded field magnets
US3659236A (en) * 1970-08-05 1972-04-25 Us Air Force Inhomogeneity variable magnetic field magnet
US3767927A (en) * 1970-08-28 1973-10-23 Philips Corp Electron beam apparatus with beam-stabilization system
US3655902A (en) * 1970-10-19 1972-04-11 Air Reduction Heating system for electron beam furnace
US3673528A (en) * 1971-03-01 1972-06-27 Gen Electric Wide frequency response line scan magnetic deflector
US4281251A (en) * 1979-08-06 1981-07-28 Radiation Dynamics, Inc. Scanning beam deflection system and method
US4922106A (en) * 1986-04-09 1990-05-01 Varian Associates, Inc. Ion beam scanning method and apparatus
US4980562A (en) * 1986-04-09 1990-12-25 Varian Associates, Inc. Method and apparatus for high efficiency scanning in an ion implanter
WO1988001731A1 (fr) * 1986-08-25 1988-03-10 Eclipse Ion Technology, Inc. Exploration parallele rapide par faisceaux ioniques ayant une lentille magnetique bipolaire avec champ non uniforme
US4745281A (en) * 1986-08-25 1988-05-17 Eclipse Ion Technology, Inc. Ion beam fast parallel scanning having dipole magnetic lens with nonuniform field
US5053627A (en) * 1990-03-01 1991-10-01 Ibis Technology Corporation Apparatus for ion implantation
US5279723A (en) * 1992-07-30 1994-01-18 As Represented By The United States Department Of Energy Filtered cathodic arc source
US5347254A (en) * 1993-03-08 1994-09-13 The United States Of America As Represented By The Secretary Of The Army Tubular structure having transverse magnetic field with gradient
WO1999017865A1 (fr) * 1997-10-07 1999-04-15 University Of Washington Separateur magnetique pour dispersion lineaire et procede de fabrication
US6182831B1 (en) 1997-10-07 2001-02-06 University Of Washington Magnetic separator for linear dispersion and method for producing the same
US20020162774A1 (en) * 1997-10-07 2002-11-07 The University Of Washington Magnetic separator for linear dispersion and method for producing the same
US20040149904A1 (en) * 1997-10-07 2004-08-05 The University Of Washington Magnetic separator for linear dispersion and method for producing the same
US6843375B2 (en) 1997-10-07 2005-01-18 The University Of Washington Magnetic separator for linear dispersion and method for producing the same
US6906333B2 (en) 1997-10-07 2005-06-14 University Of Washington Magnetic separator for linear dispersion and method for producing the same
US20040084636A1 (en) * 2000-03-27 2004-05-06 Berrian Donald W. System and method for implanting a wafer with an ion beam
US6833552B2 (en) 2000-03-27 2004-12-21 Applied Materials, Inc. System and method for implanting a wafer with an ion beam
US6661016B2 (en) 2000-06-22 2003-12-09 Proteros, Llc Ion implantation uniformity correction using beam current control

Also Published As

Publication number Publication date
BE509097A (fr)
GB753562A (en) 1956-07-25
CH302299A (de) 1954-10-15
DE911878C (de) 1954-05-20
FR1058851A (fr) 1954-03-19

Similar Documents

Publication Publication Date Title
US2777958A (en) Magnetic electron lens
JP4759113B2 (ja) 荷電粒子ビームカラム
US2274586A (en) Cathode ray tube
USRE25091E (en) Cathode-ray tubes of the lenticular grill variety
US3448316A (en) Cathode ray tube
US2454345A (en) Cathode-ray deflection tube with electron lenses
US3496406A (en) Cathode ray tubes with electron beam deflection amplification
US6232601B1 (en) Dynamically compensated objective lens-detection device and method
US3651359A (en) Abberation correction of plurality of beams in color cathode ray tube
US3896331A (en) Electron optical system
US3497763A (en) Grid to compensate for astigmatic quadrupolar lens
US2909688A (en) Magnetic means for deflecting electron beams
US3619686A (en) Color cathode-ray tube with in-line plural electron sources and central section of common grid protruding toward central source
US2939954A (en) X-ray shadow microscope
US3883771A (en) Collinear electron gun system including accelerating grid having greater effective thickness for off axis beams
US4475044A (en) Apparatus for focus-deflecting a charged particle beam
US2986668A (en) Cathode ray tube optical system
US4205254A (en) Electron gun for a cathode ray tube
US3678329A (en) Cathode ray tube
JPS6117095B2 (fr)
US2836752A (en) Beam generating system for cathoderay tubes employing an ion trap
US4495439A (en) Magnetic focusing type cathode ray tube
US2123161A (en) Television tube
US3875446A (en) Acute angle source of plural beams for color cathode ray tube
US3389252A (en) Electron microscope having a four-pole electron-optical lens assembly and a scanning line-like electron beam