Simultaneous ion detection in a double focusing mass spectrometer with specially shaped magnetic pole faces

doi:10.1016/0168-1176(86)85063-7

International Journal of Mass Spectrometry and Ion Processes

Volume 70, Issue 1, 28 May 1986, Pages 79-96

International Journa...

https://doi.org/10.1016/0168-1176(86)85063-7 Get rights and content

Abstract

The entrance and exit pole faces of the magnetic sector of a Nier-Johnson-type mass spectrometer were designed to allow the simultaneous recording of ions over a Δm/m range of 11% with a micro-channelplate detector. The aim was to obtain a flat focal plane perpendicular to the main trajectory by shaping the exit plane of the magnetic sector. The position of the focal plane of the mass spectrometer was determined by first-order calculations, neglecting the fringing field effects. The angular aberration coefficient was minimized by specially shaping the entrance plane of the magnetic sector. The exit plane had to be defined by a fourth-order polynomial, whereas for the entrance plane of the sector magnet a second-order polynomial sufficed. By third-order matrix calculation, the fringing fields were taken into account and the double focusing condition was proved to hold over the mass range considered, i.e. the planes for energy and angular focusing coincided. Mass spectra were recorded with a position-sensitive micro-channelplate detector. A mass resolution of 3000 FWHM was obtained in the simultaneous detection mode over a total length of 30 mm, whereas in the scanning mode the normal high resolving power was obtained.

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Simultaneous ion detection in a double focusing mass spectrometer with specially shaped magnetic pole faces

Abstract

Int. J. Mass Spectrom. Ion Phys.

Int. J. Mass Spectrom. Ion Phys.

Int. J. Mass Spectrom. Ion Phys.

Int. J. Mass Spectrom. Ion Phys.

Int. J. Mass Spectrom. Ion Phys.

Nucl. Instrum. Methods

Nucl. Instrum. Methods

Int. J. Mass Spectrom. Ion Processes

Mass Spectrom. Rev.

Z. Phys.

Anal. Chem.

J. Phys. E

Rev. Sci. Instrum.