GB693444A - Improvements relating to the correction of spherical aberration in electron lenses - Google Patents
Improvements relating to the correction of spherical aberration in electron lensesInfo
- Publication number
- GB693444A GB693444A GB1805550A GB1805550A GB693444A GB 693444 A GB693444 A GB 693444A GB 1805550 A GB1805550 A GB 1805550A GB 1805550 A GB1805550 A GB 1805550A GB 693444 A GB693444 A GB 693444A
- Authority
- GB
- United Kingdom
- Prior art keywords
- foil
- foils
- negative
- spherical aberration
- respect
- 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
Links
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
- H01J29/56—Arrangements for controlling cross-section of ray or beam; Arrangements for correcting aberration of beam, e.g. due to lenses
- H01J29/566—Arrangements for controlling cross-section of ray or beam; Arrangements for correcting aberration of beam, e.g. due to lenses for correcting aberration
Landscapes
- Electron Beam Exposure (AREA)
Abstract
693,444. Electron lenses. ASSOCIATED ELECTRICAL INDUSTRIES, Ltd. June 15, 1951 [July 19,1950], No. 18055/50. Class 39(i). The positive spherical aberration of a magnetic or electrostatic lens is compensated by the negative spherical aberration of a system of two or more planar conductive electron-permeable foils held at suitable potentials. The system preferably comprises three foils of which the middle one is negative with respect to the outer two, but may alternatively comprise four or two foils. In the former case the two inner foils are negative with respect to the two outer foils and the spacing between the two inner foils is greater than the inner-outer foil spacing. In the latter case the foil further from the electron source is negative with respect to the other foil. Equations for the spherical aberration of the foil systems are given, and the arrangements are especially applicable to electron microscopes. A single foil would work in theory owing it is stated to the potential inside the foil being negative with respect to the potential outside it but the foil would have to be so thick that electrons could not penetrate it.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1805550A GB693444A (en) | 1950-07-19 | 1950-07-19 | Improvements relating to the correction of spherical aberration in electron lenses |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1805550A GB693444A (en) | 1950-07-19 | 1950-07-19 | Improvements relating to the correction of spherical aberration in electron lenses |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB693444A true GB693444A (en) | 1953-07-01 |
Family
ID=10105861
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1805550A Expired GB693444A (en) | 1950-07-19 | 1950-07-19 | Improvements relating to the correction of spherical aberration in electron lenses |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB693444A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0156431A1 (en) * | 1984-03-16 | 1985-10-02 | Koninklijke Philips Electronics N.V. | Cathode ray tube |
-
1950
- 1950-07-19 GB GB1805550A patent/GB693444A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0156431A1 (en) * | 1984-03-16 | 1985-10-02 | Koninklijke Philips Electronics N.V. | Cathode ray tube |
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