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. 29, 1997
Filed:
Sep. 22, 1995
Applicant:
Inventor:
Bernd Laser, Stuhr, DE;
Assignee:
Finnigan Mat GmbH, Bremen, DE;
Primary Examiner:
Int. Cl.
CPC ...
H01J / ; G01N / ; B01J / ;
U.S. Cl.
CPC ...
250288 ; 250281 ;
Abstract
In mass spectrometers with a plasma ion source (ICP-MS), a high ion current takes effect on the entrance of the ion optical system. The components provided there, especially lenses and apertures, have hitherto been made of steel. Atoms and ions are released from the surface of the components by a sputtering effect. This results in a correspondingly spoiling background signal and in losses in the quality of the analysis. To avoid the described effects, the components which are subjected to ion bombardment are made of graphite. The sputter rate and the ion yield of the carbon are much lower than those of steel (iron, nickel and chromium).