Efficiency of an electrostatically focused electron impact ion source

✍ Scribed by Ozard, J. M. ;Russell, R. D.

• Publisher: Springer
• Year: 1969
• Tongue: English
• Weight: 254 KB
• Volume: 20
• Category: Article
• ISSN: 0003-6994
• DOI: 10.1007/bf00382382

✦ Synopsis

Naidu [1] iI~vestigated the inverse problem of particle motion which specifies the eleetrostatic field to guide charged partieles along a prescribed set of paraxial paths. As an example, art applicatiort to mass spectrometry was cited. F r o m the theory an electric field was specified t h a t should focus charged particles so that a gas source of greater efficiency than a modified Nier source appeared possible.

An ion source is constructed employing the proposed focusing field. Experimentally the new souree is fourtd to have art overall efficiency of 4 × 10 -~, the same as the modified Nier source. The new iort souree produces ions of 0.1 eV energy spread and a halt angle of divergence of 0.5 deg. An explanation for the observed efficiency is given, and the reasons for the failure to improve the performance as predicted by Naidu are discussed.