Ion detector with bipolar accelerating electrode

US4267448A · kind A · utility

Assignee

• Varian Mat GmbH

Inventors

• Karl Feser · Hamburg, DE
• Curt Brunnee · Ritterhude, DE

Key dates

• Filing date: Jun 4, 1979
• Grant date: May 12, 1981
• Expiry date: Jun 4, 1999

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01J49/025
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

The ion detector of a mass spectrometer includes an accelerating electrode 10, 34, 38 disposed between the spectrometer discharge shutter 6 and a secondary electron multiplier 18. The electrode 10 is selectively energized by a high positive or negative voltage opposite the initial polarity of the ions by a source 16. Thus, a positively energized electrode draws in and accelerates negative ions, and strips away their electrons to leave them positively charged for further acceleration into the first dynode of the secondary electron multiplier.