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:
Apr. 01, 2008
Filed:
Oct. 06, 2004
Iouri Kalinitchenko, Berwick, AU;
Iouri Kalinitchenko, Berwick, AU;
Varian Australia Pty Ltd, Mulgrave, Victoria, AU;
Abstract
An electrode for use in a reduced pressure region in a mass spectrometer whereby the electrode is subject to deposition of dielectric (non-conducting) substances thereon, which can cause unstable performance of the mass spectrometer. The surface portion of the electrode that is for providing an equipotential boundary of an electric field for influencing charged particles is made rough, in contrast to the prior art of providing a polished surface. The rough surface provides projections and cavities, which may have a regular or irregular occurrence, which it has been found significantly reduces the deposition of dielectric substances from the charged particles thereon. A preferred structure is for a rod electrode () to have a screw thread () formed thereon whereby the thread crests () along the rod electrode provide projections () and the thread roots () provide cavities.