Bainbridge–Jordan

The sector instrument geometry consists of a 127.30° ${\displaystyle \left({\frac {\pi }{\sqrt {2}}}\right)}$ electric sector without an initial drift length followed by a 60° magnetic sector with the same direction of curvature. Sometimes called a "Bainbridge mass spectrometer," this configuration is often used to determine isotopic masses. A beam of positive particles is produced from the isotope under study. The beam is subject to the combined action of perpendicular electric and magnetic fields. Since the forces due to these two fields are equal and opposite when the particles have a velocity given by

${\displaystyle v=E/B\,}$

they do not experience a resultant force; they pass freely through a slit, and are then subject to another magnetic field, transversing a semi-circular path and striking a photographic plate. The mass of the isotope is determined through subsequent calculation.

Mattauch–Herzog

The Mattauch–Herzog geometry consists of a 31.82° (${\displaystyle \pi /4{\sqrt {2}}}$ radians) electric sector, a drift length which is followed by a 90° magnetic sector of opposite curvature direction.^[4] The entry of the ions sorted primarily by charge into the magnetic field produces an energy focussing effect and much higher transmission than a standard energy filter. This geometry is often used in applications with a high energy spread in the ions produced where sensitivity is nonetheless required, such as spark source mass spectrometry (SSMS) and secondary ion mass spectrometry (SIMS).^[5] The advantage of this geometry over the Nier–Johnson geometry is that the ions of different masses are all focused onto the same flat plane. This allows the use of a photographic plate or other flat detector array.

Nier–Johnson

The Nier–Johnson geometry consists of a 90° electric sector, a long intermediate drift length and a 60° magnetic sector of the same curvature direction.^[6][7]

Hinterberger–Konig

The Hinterberger–Konig geometry consists of a 42.43° electric sector, a long intermediate drift length and a 130° magnetic sector of the same curvature direction.

Takeshita

The Takeshita geometry consists of a 54.43° electric sector, and short drift length, a second electric sector of the same curvature direction followed by another drift length before a 180° magnetic sector of opposite curvature direction.

Matsuda

The Matsuda geometry consists of an 85° electric sector, a quadrupole lens and a 72.5° magnetic sector of the same curvature direction.^[8] This geometry is used in the SHRIMP and Panorama (gas source, high-resolution, multicollector to measure isotopologues in geochemistry).