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:
Aug. 11, 2009
Filed:
Jan. 22, 2007
Applicants:
John W. Lewellen, Willowbrook, IL (US);
John Noonan, Naperville, IL (US);
Inventors:
John W. Lewellen, Willowbrook, IL (US);
John Noonan, Naperville, IL (US);
Assignee:
UChicago Argonne, LLC, Chicago, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J 37/73 (2006.01);
U.S. Cl.
CPC ...
Abstract
A method and an electron source are provided for generating polarized electrons for an electron microscope. The electron source includes a photoemissive cathode and a low-power drive laser. The geometry of the photoemissive cathode uses a generally planar emission surface, which is imaged to approximately 1/100 its initial size via electrostatic focusing elements. The virtual emitter, or image spot, then is used as an electron source by a conventional microscope column.