An improved Auger electron spectrometer using concentric hemispheres

An improved Auger electron spectrometer is presented, using concentric hemispheres accessed by retarding electron lenses. Two modes of operation are available. The first is a constant resolving power mode in which the resolving power is variable from 500 to 4000, by selection of working distance and applied potentials. The collection efficiency is 0.2% of 2 pi sr at a resolving power of 500. The second is a constant hemisphere pass energy mode. By consecutive use of the two modes, the spectrometer will scan from 1 eV to 2 keV. The collection efficiency can be increased to 3% at a resolving power of 300 but aberrations degrade the performance. The analyser is mounted on an 8 in Conflat flange. Finally, the Auger spectrum of lithium is presented.