Fourier transform mass spectrometry in an ECR plasma

Abstract

Consideration has been given to the use of Fourier transform mass spectrometry (FTMS) to provide in-situ mass measurements of active species in an electron cyclotron resonance (ECR) plasma reactor. An ECR plasma was produced in a vacuum chamber placed inside a DC magnetic mirror field by microwaves whose power level could be adjusted up to 2 kW CW. The electron cyclotron resonance was adjusted to be approximately 25% of the distance from the throat of the mirror to the mid-plane of the vacuum chamber. The mirror ratio was 2:1, the operating gas was argon, and the pressure was set to 2*10/sup -4/ torr. FTMS took place in a cubical cell placed in the center of the magnetic mirror region where the magnetic field was most uniform.<>