Patent ID: 7053367
Filing Date: 2006-05-30
Classification: H01J

Abstract:
1. A mass spectrometer comprising: an ionization section for ionizing a sample at substantially atmospheric pressure; a first and a second intermediate pressure section in which the pressure is maintained lower than the pressure in said ionization section; a high vacuum section in which the pressure is maintained lower than the pressure in said intermediate pressure section and in which a mass spectrometric means for subjecting ions to mass spectrometry is disposed; a first pore electrode disposed between said ionization section and said first intermediate pressure section; an intermediate pore electrode disposed between said first intermediate pressure section and said second intermediate pressure section; and a second pore electrode disposed between said second intermediate pressure section and said high vacuum section, wherein: ions produced in said ionization section are introduced via said first pore electrode, said intermediate pore electrode, and said second pore electrode to said high vacuum section, in which mass spectrometry is performed, and wherein: a first converging electrode is provided in said first intermediate pressure section, said first converging electrode having an opening towards said first pore electrode and another opening towards said intermediate pore electrode, the opening towards said first pore electrode having a larger diameter than the opening towards said intermediate pore electrode, such that said first converging electrode has a tapered shape.