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It has very high selectivity over other metal ions and anions.
Low-energetic negative ions are, however, less affected by changes of the target material.
Our data indicate that nearly 100% of the negative ions recombine with the positive ions.
We find good agreement with the existing results for atomic negative ions.
We find negative ions to be solvated more strongly compared to positive ions of equal size, in agreement with experimen- tal data.
The results give more knowledge of the long-lived negative ions formation.
Journal ArticleDOI
P. F. Knewstubb, T. M. Sugden 
01 Dec 1962-Nature
21 Citations
This has so far largely been used for positive ions2,3, but it is adaptable to the study of negative ions, albeit with a somewhat reduced sensitivity.
Models are beginning to explain the low mass negative ions, but the formation process for the higher mass ions is still not understood.

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