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Ion Source for Mass Spectrometer

IP.com Disclosure Number: IPCOM000091726D
Original Publication Date: 1968-May-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 20K

Publishing Venue

IBM

Related People

Lever, RF: AUTHOR [+2]

Abstract

The ion source is used in a monopole mass spectrometer. Filaments F eject electrons through arcuate grid G. The electrons from filaments F collide with molecules contained within grid G to produce ions which exit through opening H. Those ions having a suitable trajectory are then focused by other electrodes, not shown, and enter a monopole mass filter as their mass is determined. Thus, the sensitivity of the instrument depends on the number of ions emerging through opening H which have trajectories suitable for focussing in the mass filter. The field pattern created by the arcuate shape of grid G is axially symmetrical about the direction of exit.

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Ion Source for Mass Spectrometer

The ion source is used in a monopole mass spectrometer. Filaments F eject electrons through arcuate grid G. The electrons from filaments F collide with molecules contained within grid G to produce ions which exit through opening H. Those ions having a suitable trajectory are then focused by other electrodes, not shown, and enter a monopole mass filter as their mass is determined. Thus, the sensitivity of the instrument depends on the number of ions emerging through opening H which have trajectories suitable for focussing in the mass filter. The field pattern created by the arcuate shape of grid G is axially symmetrical about the direction of exit. Such arrangement results in a higher proportion of ions having favorable trajectories and a higher proportion exiting from H in a direction having a small angle of inclination to the axis.

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