Surface Production of Ions
Abstract
It has been shown that negative hydrogen ions can be produced with high efficiency by backscattering low energy (order of 1 eV) hydrogen atoms or ions from low work-function (less than 1.5 eV) surfaces. This has been demonstrated experimentally by backscattering the Maxwellian tail of thermally produced hydrogen atoms from a variety of low work function surfaces. The general nature of the electron transfer process has been described by a simple theoretical model. Low incident energy guarantees low energy spread of the negative hydrogen ions. It also makes it possible to consider a variety of adsorbates for reducing the work function of the converter surface. The work function of cesium-oxygen films on silicon can be as low as 0.9 eV but these films are too delicate for use on converter surfaces. Thick cesium oxide films with a work function ranging from 1.2 to 1.4 eV have been successfully used on converter surfaces. Surface production of cesium ions from solid electrolyte sources has been investigated. Three types of cesium ion guns were developed and used in the experiments. Keywords: Ion emission; Ion sources; Atom; Molecule and ion impact.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 09, 1989
- Accession Number
- ADA216470
Entities
People
- Milos Seidl
Organizations
- Stevens Institute of Technology