Surface Ionization Source Using Multiple Filaments

A new multiple filament surface ionization source has been developed for mass spectrometry which for several of the elements is many times more efficient than the usual single filament surface ionization source. Emission from the source can be shifted from the oxide to the metal position or vice versa by appropriate adjustment of temperatures. Because of the high efficiency of the source it is possible to look at the sample during a number of successive evaporations. Use of this source should eliminate the necessity of using electron multiplier ion detection for some elements.