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:
Feb. 10, 1976
Filed:
Mar. 31, 1975
Thomas W Rusch, Falcon Heights, MN (US);
Jerry A Sievers, Stillwater, MN (US);
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Abstract
A charged particle beam (e.g., ions or electrons) apparatus including two electrostatic focusing lenses and an electrode having a diameter limiting aperture positioned between the lenses is further provided with two electrode assemblies which interact with an extractor electrode and with a source of charged particles such that the trajectories of the particles in the beam passing through the second of the two assemblies are substantially parallel. This feature and other disclosed improvements facilitate the production of a substantially monoenergetic beam which under a first set of conditions can be focused to provide a small-diameter, spherical-aberration limited beam and which under another set of conditions, can be focused to provide a high current beam.