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:
Nov. 12, 2002
Filed:
Dec. 04, 2001
Mark Dinsmore, Sudbury, MA (US);
Photoelectron Corporation, North Billerica, MA (US);
Abstract
A therapeutic radiation source includes a optically heated thermionic cathode that is shaped so as to maximize the coupling efficiency of the incident optical radiation to the thermionic cathode. A fiber optic cable directs a beam of radiation, having a power level sufficient to heat at east a portion of the electron-emissive surface to an electron emitting temperature, from a laser source onto the cathode. An electron beam generated by said cathode strikes a target which is positioned in its beam path and which emits therapeutic radiation in response to incident accelerated electrons from the electron beam. The thermionic cathode has a non-planar configuration, such as a conical shape and a concave shape, adapted to allow an incident ray of optical radiation to impinge upon, and undergo absorption from, a plurality of regions within the surface of the cathode in succession.