2π-radian field-of-view toroidal electrostatic analyzer

Abstract

We describe a new type of electrostatic charged particle analyzer based on toroidal geometry. The analyzer features a 360°×10° (polar×azimuthal) field of view and a focal length in the polar direction significantly longer than that of similar devices based on spherical geometry. Extended focal length is a requirement for matching the electrostatic energy spectrometer with a second, mass-resolving, analyzer. Laboratory tests show that the toroid design has a large geometric factor per unit of instrument weight, good energy-angle resolution in the particle deflection plane, and sharp (1.0° FWHM) resolution at focus in the polar angle direction. The analyzer is well suited for use in satellite-borne mass spectrometry and also as a stand-alone electrostatic analyzer.