Nier-type ion source

Several other observations of a variety of doubly-charged negative ions have been made by different investigators using different experimental approaches. The experimental methods employed do, however, have some common bases. The experiments described below involve different ion sources, but these can be classified into two main categories conventional Nier-type ion sources and relatively cool plasma sources. The experiments of Ahnell and Koski Dougherty and Bowie and Stapleton involve the Nier-type ion sources. The experiments of Schnitzer and Anbar and Stapleton and Bowie like those of Baumann, Heinicke,... 

The above mechanisms for the formation of and S are plausible and explain the observation of 0 and S by Stuckey and Kiser and by Baumann, Heinicke, Kaiser and Bethge. They specifically involve excited states both of Z and of Z. And the lifetime of the Z would permit significant concentrations of Z to be formed in a plasma source, such as found in the omegatron or the Penning source. However, it is anticipated that only much lower concentrations of Z would be formed in the Nier-type ion source employed in most conventional mass spectrometers. It is unlikely, therefore, that the above mechanisms can satisfactorily account for the observation of F formed from CF3CI, as reported by Ahnell and Koski or the various Z species reported by Bowie and Stapleton ... 

The reactions were studied with a 6-inch 60°-sector mass spectrometer. The ion source is of the Nier type (11), machined from a block of... 

In that instrument, ions were extracted from a Nier-type electron impact source by... 

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