The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 17, 1992
Filed:
Sep. 25, 1990
Ondrej L Krivanek, Oakland, CA (US);
Gatan, Inc., Pleasanton, CA (US);
Abstract
A method and an apparatus comprising an electron gun, two energy analyzers, an energy-selecting slit with intensity sensors, a feedback circuit, a sample, and an electron detector. The beam produced by the electron gun is dispersed according to the energies of the electrons by the first energy analyzer. The dispersed beam impinges on a slit which monochromates the beam by selecting a narrow pass-band of energies. The two halves of the slit are equipped with electron intensity sensors whose output is used by a feedback circuit to stabilize the position of the dispersed beam on the slit so as to counteract instabilities in the power supplies of the electron gun and of the analyzer. The monochromated electron beam then passes through a sample, and the transmitted beam is dispersed according to the energies of the electrons by the second energy analyzer. The power supplies of the two analyzers are linked so that the energy selected by the second analyzer tracks the energy selected by the first analyzer. The second analyzer therefore automatically tracks instabilities in the gun high voltage, and the whole apparatus is able to achieve much higher energy resolution than if all the power supplies were operated independently.