Apparatus and process for improved detection limits in mass spectrometry

摘要

A system and method for detecting trace levels of a sample gas in a mass spectrometer having a vacuum chamber with a vacuum pump, an ionizer, extracting and imaging lens and a detector. A high pressure sample gas pulse is introduced into the vacuum chamber through a small orifice to produce a high density of sample gas in a region near the orifice. The density of the sample gas pulse is sufficient to substantially sweep residual background gas from the path of the pulse. A portion of the sample gas pulse is ionized and ions are extracted and imaged.