US2993993A - Diaphragm for limiting the field of view of three-stage electron microscopes - Google Patents

Diaphragm for limiting the field of view of three-stage electron microscopes Download PDF

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Publication number
US2993993A
US2993993A US821051A US82105159A US2993993A US 2993993 A US2993993 A US 2993993A US 821051 A US821051 A US 821051A US 82105159 A US82105159 A US 82105159A US 2993993 A US2993993 A US 2993993A
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United States
Prior art keywords
diaphragm
view
limiting
field
rod
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Expired - Lifetime
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US821051A
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English (en)
Inventor
Delong Armin
Drahos Vladimir
Specialny Jan
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Tesla AS
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Tesla AS
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    • 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
    • H01J37/09—Diaphragms; Shields associated with electron or ion-optical arrangements; Compensation of disturbing fields

Definitions

  • the present invention relates to a diaphragm for limiting the field of view of three-stage electron microscopes with the aid of a selective diaphragm.
  • the region can be limited in three-stage electron microscopes by placing a diaphragm in the object-plane of the auxiliary lens in such a manner that the beams outside the selected region do not participate in engendering the difiraction image. In this way it is possible to ascertain what part of the observed object participates in forming the diffraction image after switching the apparatus over to diffraction work. In accordance with the character of the examined objects it is sometimes necessary to limit the observed region up to the dimensions of a single microcrystal so that different apertures of the diaphragm are necessary.
  • the aperture of the diaphragm may be adjusted as desired.
  • the adjustable diaphragms have a complicated mechanism and high costs of production with respect to the small dimensions of the aperture of the diaphragm which is to be continuously adjustable.
  • a common disadvantage of all the known diaphragms of the said kind is their uneasy handling because they require a tiresome centering.
  • the present invention removes the inconveniences of the known diaphragm systems and considerably reduces the time necessary to adjust the diaphragm.
  • the invention relates to a diaphragm for screening oif electron beams in three-stage electron microscopes, the diaphragm having a lenticular opening and being rotatable round an axis perpendicular to the optical axis of the apparatus.
  • the diaphragm consists of two members with circular openings, the openings being adapted to coincide partly with each other thereby forming the lenticular opening of the diaphragm.
  • FIG. 1 illustrates schematically a diaphragm of a known kind, showing a lozenge-shaped aperture at its maximum size
  • FIG. 2 illustrates the same diaphragm, showing the aperture at a reduced size
  • FIG. 3 represents schematically an embodiment of the diaphragm according to the invention, in the position of its maximum aperture
  • FIG. 4 shows the same diaphragm as FIG. 3 does, but with reduced aperture
  • FIG. 5 shows in sectional elevation an embodiment of the diaphragm together with its holding and operating parts
  • FIG. 6 shows the same embodiment in plan view, partlyin section.
  • FIGS. 1 and 2 one method used hitherto for changing the aperture of a diaphragm is shown in FIGS. 1 and 2.
  • the maximum aperture of the diaphragm for the electron beams is shown in FIG. 1, whereas FIG. 2 shows how the aperture may be successively reduced.
  • FIGS. 3 and 4 represent the screening off of a pencil of electron beams by a lenticular opening of the diaphragm according to the present invention.
  • FIG. 3 shows the diaphragm in a position allowing a maximum passage of the electron beams
  • FIG. 4 shows how the electron beams may be successively screened off by turning the diaphragm round its axis.
  • FIGS. 5 and 6 An embodiment of the invention is represented in FIGS. 5 and 6 showing the diaphragm with its operating members.
  • a rod 10 provided with a guide-surface 11 on one end has a screw spindle 112 on the same extremity.
  • a transverse opening 13 is arranged in the other extremity of the rod 10, the axis of said opening being perpendicu lar to the plane of the guide-surface 11.
  • a sleeve 14 is put slidably over this end of the rod 10, the sleeve having two diametrically opposite openings 15 which partly co incide with the opening 13 in the rod, thus forming a lenticular opening of the diaphragm.
  • the rod 10 is packed by an elastic packing ring 16 which is pressed towards a bearing member 17 by means of a cap-nut .18 in such a manner that the rod 10 is able to make sliding, rotating and slanting movements while maintaining a vacuum-tight connection.
  • a cap-nut 19 presses the bearing member 17 over a packing ring 20' to a wall 21 of the evacuated chamber of the apparatus.
  • a sleeve 22 is put slidably over the bearing member 17, one end of the sleeve having a spherical surface 23.
  • a ring 24 provided with a scale for indicating its angle of rotation leans against the spherical surface 23 and an adjusting nut 25 bearing a micrometer gauge leans against the ring 24, the adjusting nut being screwed on the screw spindle 12 of the rod 10.
  • a wedge 26 inserted in the ring 24 serves to transfer rotational movements of the ring 24 to the rod 10 and at the same time prevents the rod 10 from rotating during its axial movements caused by the adjusting nut 25.
  • a sleeve embracing slidably the rod 10 is engaged by two set-screws 28, 29 adapted to slant the rod 10. The rod 10 with all the parts connected with it is pressed towards the inner space of the evacuated chamber by the overpressure of the outer air and by a spring 30 leaning against a washer 31.
  • the above described device is located under the objective of an electron microscope.
  • the centre of the lenticular opening of the diaphragm may be brought into coincidence with the center of the pencil of electron beams, firstly, by axial movement of the rod effected by rotation of the adjusting nut, these movements being controllable by the micrometric scale of the nut, and secondly, by slanting movements effected by the set-screws 28 and 29.
  • the pencil of electron beams may be screened off by turning the ring 24 round the axis of the rod 10.
  • the angle of rotation is indicated by the scale arranged on the ring 24.
  • a diaphragm for variably screening the electron beam of an electron microscope comprising an elongated member having a circular bore extending diametrically therethrough, a sleeve member havingdiametrically opposed circular openings and being disposed on said elongated member with the axis of said openings extending parallel to the axis of said bore and with the axes of said openings and bore being spaced from each other in the direction of the longitudinal axis of the elongated member to provide a partial overlap of the areas of said bore and openings to define an aperture having a lenticular shape, and means supporting said elongated member for rotation about said longitudinal axis thereof and adapted to project said elongated member into the path of the electron beam with said longitudinal axis extending substantially at right angles to the direction of the electron beam and with said aperture variably screening the beam in accordance with rotational adjustment of said elongated member.

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  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)
  • Electron Sources, Ion Sources (AREA)
  • Electron Beam Exposure (AREA)
US821051A 1958-06-19 1959-06-17 Diaphragm for limiting the field of view of three-stage electron microscopes Expired - Lifetime US2993993A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CS881094X 1958-06-19

Publications (1)

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US2993993A true US2993993A (en) 1961-07-25

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US821051A Expired - Lifetime US2993993A (en) 1958-06-19 1959-06-17 Diaphragm for limiting the field of view of three-stage electron microscopes

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US (1) US2993993A (enrdf_load_stackoverflow)
DE (1) DE1125566B (enrdf_load_stackoverflow)
GB (1) GB881094A (enrdf_load_stackoverflow)
NL (1) NL113488C (enrdf_load_stackoverflow)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3333098A (en) * 1963-07-31 1967-07-25 Hitachi Ltd Aperture device for electron microscopes and the like
US3401261A (en) * 1962-01-23 1968-09-10 Siemens Ag Apparatus for investigating magnetic regions in thin material layers
US3411000A (en) * 1965-04-14 1968-11-12 Siemens Ag X-ray diffractometer diaphragm which is synchronously rotated with the specimen
US3446960A (en) * 1965-08-30 1969-05-27 Nasa Device for measuring electron-beam intensities and for subjecting materials to electron irradiation in an electron microscope
US3852594A (en) * 1973-07-25 1974-12-03 Pepi Inc X-ray diffraction apparatus
US4466112A (en) * 1982-01-29 1984-08-14 Technicare Corporation Variable detector aperture
US4602377A (en) * 1984-03-30 1986-07-22 The United States Of America As Represented By The United States Department Of Energy Diamond-anvil high-pressure cell with improved X-ray collimation system
WO2005022581A3 (en) * 2003-08-28 2005-06-02 Shimadzu Res Lab Europe Ltd Particle optical apparatus
US20110049361A1 (en) * 2009-07-24 2011-03-03 Dirk Preikszas Particle beam apparatus having an aperture unit and method for setting a beam current in a particle beam apparatus

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1216454B (de) * 1962-05-15 1966-05-12 Siemens Ag Blendenanordnung zum Ausblenden bestimmter Strahlen aus dem Strahlengang von an der Pumpe arbeitenden Korpuskularstrahlgeraeten

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1386630A (en) * 1920-06-07 1921-08-09 Charles T Kinsman Bunsen burner
US2851610A (en) * 1954-09-08 1958-09-09 Akashi Kazuhiko Variable aperture for electron microscope

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1386630A (en) * 1920-06-07 1921-08-09 Charles T Kinsman Bunsen burner
US2851610A (en) * 1954-09-08 1958-09-09 Akashi Kazuhiko Variable aperture for electron microscope

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3401261A (en) * 1962-01-23 1968-09-10 Siemens Ag Apparatus for investigating magnetic regions in thin material layers
US3333098A (en) * 1963-07-31 1967-07-25 Hitachi Ltd Aperture device for electron microscopes and the like
US3411000A (en) * 1965-04-14 1968-11-12 Siemens Ag X-ray diffractometer diaphragm which is synchronously rotated with the specimen
US3446960A (en) * 1965-08-30 1969-05-27 Nasa Device for measuring electron-beam intensities and for subjecting materials to electron irradiation in an electron microscope
US3852594A (en) * 1973-07-25 1974-12-03 Pepi Inc X-ray diffraction apparatus
US4466112A (en) * 1982-01-29 1984-08-14 Technicare Corporation Variable detector aperture
US4602377A (en) * 1984-03-30 1986-07-22 The United States Of America As Represented By The United States Department Of Energy Diamond-anvil high-pressure cell with improved X-ray collimation system
WO2005022581A3 (en) * 2003-08-28 2005-06-02 Shimadzu Res Lab Europe Ltd Particle optical apparatus
US20070138403A1 (en) * 2003-08-28 2007-06-21 Dane Cubric Particle optical apparatus
US20110049361A1 (en) * 2009-07-24 2011-03-03 Dirk Preikszas Particle beam apparatus having an aperture unit and method for setting a beam current in a particle beam apparatus
US11139140B2 (en) 2009-07-24 2021-10-05 Carl Zeiss Microscopy Gmbh Particle beam apparatus having an aperture unit and method for setting a beam current in a particle beam apparatus

Also Published As

Publication number Publication date
GB881094A (en) 1961-11-01
DE1125566B (de) 1962-03-15
NL113488C (enrdf_load_stackoverflow)

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