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:
Jul. 13, 1993
Filed:
Dec. 19, 1990
Applicant:
Inventors:
Kazutoshi Nagai, Kanagawa, JP;
Tatsuya Nishimura, Kanagawa, JP;
Assignee:
Ebara Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
315383 ; 313337 ;
Abstract
An electron accelerator includes a thermal cathode, heated by infrared rays guided by a quartz rod, for emitting electrons, an accelerating section connected to a high voltage power supply, and a vacuum vessel containing the cathode and the acceleration section. The cathode may be heated by laser beam instead of the infrared rays. The current level of an accelerated electron beam is detected to generate a signal proportional to the detected level. The signal is used to adjust the intensity of the rays heating the cathode to prevent the level of electrons emitted from said cathode from fluctuating.