Mass discrimination

1981; Elsevier BV; Volume: 37; Issue: 2 Linguagem: Inglês

10.1016/0020-7381(81)80006-x

ISSN

1873-3034

Autores

P. Coxon, G. Canadas,

Tópico(s)

Advanced Sensor Technologies Research

Resumo

The pertinent and well-known problem of the discriminative effect produced by small orifices used in mass-spectrometric ion sampling from gas discharges is one which is unfortunately not well understood. The problem has been investigated experimentally by Kingsman and Rees [1] and by Miloy and Elford [2] for particular experimental conditions. Parkes [3] has investigated the problem theoretically for high-pressure discharges, where convective flow through the hole dominates. The present communication seeks to provide a simple method for calculating ion transmission coefficients through such orifices for the special case where the gas mean free path is greater than the orifice diameter and the ions have an imposed additional axial velocity component due either to an electric-field drift velocity or to a flow velocity (flowing afterglows).

Referência(s)