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. 27, 1976
Filed:
Feb. 20, 1975
Robert Bachmann, Dottingen, CH;
Pieter Bearda, Turgi, CH;
Walter Stoidl, Gebenstorf, CH;
Gerold Brandli, Aarau, CH;
Rudolf Rieder, Wettingen, CH;
BBC Brown Boveri & Company Limited, Baden, CH;
Abstract
Apparatus for generating ultraviolet radiation of high spectral radiance whereby the radiation is produced in a discharge tube having a thermoemissive cathode and a discharge space and filled with mercury/argon by means of a wall-stabilized direct-current gas discharge at a mercury pressure p.sub.Hg of between 5 .times. 10.sup.-.sup.3 and 5 .times. 10.sup.-.sup.1 Torr and a current density j of the discharge current I of between 1 and 25 A/cm.sup.2. The discharge tube incorporates a pressure-equalizing space connecting the cathode space to the anode space whereby the sum of the volumes of the cathode space, anode space and pressure-equalizing space is greater than the volume of the discharge space. The pressure of the argon is maintained between 0.01 and 10 Torr. A first control element is provided which regulates the current density j of the discharge current I to a constant value j.sub.O between 1 and 25 A/cm.sup.2. A second control element is provided which regulates the pressure p.sub.Hg of the mercury to such a value that the yield .eta. of the line of wavelength 2537 A, i.e. the ratio of the spectral radiation power for the wavelength .lambda.= 2537 A to the electrical power stored in the discharge, is at least 80% of the maximum yield .eta..sub.max for the chosen current density j.sub.O.