Coupling of a radio frequency plasma chamber with a quadrupole mass spectrometer equipped with a field ionization source

Abstract

An r.f. plasma chamber was coupled with a field ionization (FI) source of a quadrupole mass spectrometer, in order to detect neutral species generated in glow discharge plasmas. In brief, the plasma chamber and the FI source are separated by a circular orifice, neutral species effusing from the orifice are field-ionized, and then guided to the mass spectrometer via electrostatic deflection. The mass spectrometer is also equipped with an electron impact ion source, thus allowing comparison of FI and EI mass spectra of the same plasma. Preliminary data obtained with it indicate that this instrument has promising applications for diagnosing low-temperature plasmas.