Patent ID: 9716000
Date: 2017-07-25
CPC Classifications: H01J

Claim:
1. A method for transmitting ions in a mass spectrometer from a region of higher pressure to a region of lower pressure comprising passing the ions through a gating apparatus disposed between said higher pressure region and said lower pressure region, the gating apparatus comprising: first and second electrostatic lenses, each of said lenses being operably controlled by one or more controllers capable of maintaining different voltages on each of said lenses; wherein the first lens is disposed adjacent to the region of higher pressure and having a voltage that is fixed at a predetermined value that allows traversal of ions through the first lens, and the second lens is disposed adjacent to the region of lower pressure and being situated downstream from said first lens, said second lens having a voltage that varies between at least two different voltages wherein in the first voltage, the ions can traverse through said second lens and in said second voltage, the ions are preventing from traversing through said second lens.