GB665094A - Improvements relating to the reduction of primary spherical aberration in magnetic electron lenses - Google Patents

Improvements relating to the reduction of primary spherical aberration in magnetic electron lenses

Info

Publication number
GB665094A
GB665094A GB9775/47A GB977547A GB665094A GB 665094 A GB665094 A GB 665094A GB 9775/47 A GB9775/47 A GB 9775/47A GB 977547 A GB977547 A GB 977547A GB 665094 A GB665094 A GB 665094A
Authority
GB
United Kingdom
Prior art keywords
lens
magnetic
electrostatic
electron
focal length
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
Application number
GB9775/47A
Inventor
Gerhard Liebmann
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.)
Associated Electrical Industries Ltd
Original Assignee
Associated Electrical Industries Ltd
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 Associated Electrical Industries Ltd filed Critical Associated Electrical Industries Ltd
Priority to GB9775/47A priority Critical patent/GB665094A/en
Priority to US54381A priority patent/US2486856A/en
Publication of GB665094A publication Critical patent/GB665094A/en
Expired legal-status Critical Current

Links

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, ion-optical arrangement
    • H01J37/10—Lenses
    • H01J37/145—Combinations of electrostatic and magnetic lenses

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Electron Beam Exposure (AREA)

Abstract

665,094. Electron lenses. ASSOCIATED ELECTRICAL INDUSTRIES, Ltd. April 12, 1948 [April 12, 1947], No. 9775/47. Class 39 (i). The primary spherical aberration caused by a converging magnetic electron lens is compensated by combining therewith a diverging electrostatic. lens of which the marginal focal length is smaller than the paraxial focal length; the electrostatic lens is formed by a plane electron permeable metal film 6, Fig. 1. and a cylinder 4, the cylinder 4 forming one of the pole pieces of the magnetic lens, and the metal film 6 being mounted on the other pole-piece 3, as shown. 5 is a brass spacer and sleeve 8 insulates member 4 from shroud 2. Fluctuations in accelerating voltage can be made to appear also between electrodes 4, 6 and the resulting fluctuations in the focal length of the electrostatic lens can be made to compensate for the corresponding fluctuations in focal length of the magnetic lens. Alternatively, two electrostatic correcting lenses may be used. one correcting spherical aberration and the other correcting chromatic aberration due to voltage fluctuations. In a modified construction, Fig. 2 (not shown), the objective and projector lens of an electron microscope each comprise a combined magnetic and electrostatic lens. The metal films used may be of aluminium or beryllium evaporated on to a thin plastic film, or may be stretched tightly over a suitable frame. The invention is applicable to high voltage cathode-ray tubes, electron microscopes, and to fine focus X-ray tubes. The magnetic lens be operated as described in Specification 665,111. The Provisional Specification refers in addition to ion optical lens systems and states that the metal film may be curved.
GB9775/47A 1947-04-12 1947-04-12 Improvements relating to the reduction of primary spherical aberration in magnetic electron lenses Expired GB665094A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB9775/47A GB665094A (en) 1947-04-12 1947-04-12 Improvements relating to the reduction of primary spherical aberration in magnetic electron lenses
US54381A US2486856A (en) 1947-04-12 1948-10-14 Electron lens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9775/47A GB665094A (en) 1947-04-12 1947-04-12 Improvements relating to the reduction of primary spherical aberration in magnetic electron lenses

Publications (1)

Publication Number Publication Date
GB665094A true GB665094A (en) 1952-01-16

Family

ID=9878528

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9775/47A Expired GB665094A (en) 1947-04-12 1947-04-12 Improvements relating to the reduction of primary spherical aberration in magnetic electron lenses

Country Status (2)

Country Link
US (1) US2486856A (en)
GB (1) GB665094A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3201585A (en) * 1963-10-30 1965-08-17 Ballam Joseph Magnetic momentum analyzing slit with current conducting strips secured to the magnetic poles
US3385965A (en) * 1965-08-10 1968-05-28 Gen Electric Ion source having a hollow cylindrical permanent magnet maintained at a positive potential relative to the electron emitter
EP0088457A2 (en) * 1982-02-26 1983-09-14 Philips Electronics Uk Limited Charged particle beam apparatus
US8642959B2 (en) 2007-10-29 2014-02-04 Micron Technology, Inc. Method and system of performing three-dimensional imaging using an electron microscope

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB648118A (en) * 1948-11-25 1950-12-28 Frederick Henry Townsend Improvements in or relating to cathode ray tubes with magnetic deflection
US2619607A (en) * 1951-03-10 1952-11-25 Glaser Steers Corp Internal focusing device
NL192009A (en) * 1953-11-02
NL185815B (en) * 1954-03-11 Bayer Ag PROCEDURE FOR CONTROLLING MICRO-ORGANISMS AND FORMED PRODUCTS, WHOLE OR PARTLY CONSISTING OF MATERIAL, TREATED IN ACCORDANCE WITH THIS PROCEDURE.
NL97470C (en) * 1955-03-15
DE1134769B (en) * 1959-08-22 1962-08-16 Zeiss Carl Fa Device for compensating the opening error of a rotationally symmetrical, space charge-free electron-optical lens
NL255680A (en) * 1959-09-23
WO2007146985A2 (en) * 2006-06-13 2007-12-21 Semequip, Inc. Magnetic analyzer apparatus and method for ion implantation

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3201585A (en) * 1963-10-30 1965-08-17 Ballam Joseph Magnetic momentum analyzing slit with current conducting strips secured to the magnetic poles
US3385965A (en) * 1965-08-10 1968-05-28 Gen Electric Ion source having a hollow cylindrical permanent magnet maintained at a positive potential relative to the electron emitter
EP0088457A2 (en) * 1982-02-26 1983-09-14 Philips Electronics Uk Limited Charged particle beam apparatus
EP0088457A3 (en) * 1982-02-26 1986-08-27 Philips Electronic And Associated Industries Limited Charged particle beam apparatus
US8642959B2 (en) 2007-10-29 2014-02-04 Micron Technology, Inc. Method and system of performing three-dimensional imaging using an electron microscope
US9390882B2 (en) 2007-10-29 2016-07-12 Micron Technology, Inc. Apparatus having a magnetic lens configured to diverge an electron beam

Also Published As

Publication number Publication date
US2486856A (en) 1949-11-01

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