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. 04, 1986
Filed:
Oct. 09, 1984
Richard D Faulkner, Manheim Township, Lancaster County, PA (US);
RCA Corporation, Princeton, NJ (US);
Abstract
A method of processing a bialkali-antimonide photoemissive cathode to remove trace quantities of alkali metal impurities is disclosed. The cathode is formed by heating alkali vapor sources comprising the chromates of two alkali materials which include trace impurities of two other alkali materials of higher vapor pressures than the aforementioned two alkali materials to sufficiently high temperatures to produce alkali vapors. The temperature of the substrate onto which the various alkali vapors condense is maintained at a sufficiently high temperature for a sufficiently long period of time to drive off the trace quantities of the higher vapor pressure other alkali materials from the substrate. Additionally, after the alkali vapor sources are heated to temperatures sufficient to vaporize the alkali chromates therein, the temperatures of the sources are lower and maintained at sufficient levels to accelerate the removal of reduced alkali vapors from the sources and from the photomultiplier tube.