Mattauch–Herzog geometry

https://doi.org/10.1351/goldbook.M03761
An arrangement for a double-focusing
mass spectrograph
in which a deflection of π4 2 radians in a radial electrostatic field is followed by a magnetic deflection of π2 radians.
Source:
PAC, 1991, 63, 1541. (Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991)) on page 1546 [Terms] [Paper]