DESIGN AND PERFORMANCE OF A HIGH-RESOLUTION ELECTRON-ENERGY ANALYZER FOR ANGLE-RESOLVED PHOTOEMISSION SPECTROSCOPY

The design and performance of a solid-state angle-resolved photoemission (ARP) spectrometer is described. The electron energy analyzer is based on a 180° hemispherical electrostatic deflector, the design being optimized for energy resolution and sensitivity. Using He(I) (hν=21.2 eV) excited ARP spectra of the Cu(001) M¯ Tamm state, the empirically determined energy resolution is found to approach the theoretical limit. With the current choice of defining apertures the theoretical limit (for the Tamm state) is 14 meV, and the angular resolution is ±2°. The observation of previously unresolved thermal effects on the intensity, inverse lifetime and binding energy of the Tamm state feature illustrates a typical application of the instrument.