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.

Date of Patent:
Feb. 18, 2003

Filed:

Oct. 22, 1999
Applicant:
Inventors:

Steven R. Walther, Andover, MA (US);

Nicholas R. White, Wenham, MA (US);

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G21K 1/08 ; H01J 3/14 ; H01J 3/26 ; H01J 4/942 ;
U.S. Cl.
CPC ...
G21K 1/08 ; H01J 3/14 ; H01J 3/26 ; H01J 4/942 ;
Abstract

Methods and apparatus are provided for scanning a charged particle beam. The apparatus includes scan elements and a scan signal generator for generating scan signals for scanning the charged particle beam in a scan pattern having a scan origin. In one embodiment, the apparatus includes a position controller for positioning the scan elements based on a parameter of the charged particle beam, such as energy. The scan elements may be positioned to achieve a fixed position of the scan origin for different beam energies. In another embodiment, the apparatus includes first and second sets of scan elements and a scan signal controller for controlling the scan signals supplied to the sets of scan elements based on a parameter of the charged particle beam, such as energy. The scan signal controller may control the ratio of the scan signals applied to the sets of scan elements, or may deenergize a set of scan elements, to minimize space charge forces on the charged particle beam that may reduce beam transmission through the apparatus.


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