Microwave excited helium plasma photoionization detector

摘要

A photoionization detector for detecting effluents from a gas chromatographic column has a microwave induced helium plasma as the photon source. Since the source plasma may be at atmospheric pressure and need not be sealed, energy loss due to transmission of photons through a window can be eliminated. Use of alternating electromagnetic fields instead of a direct current discharge obviates the problems of anode sputtering.