LATEST DEVELOPMENTS IN (E,2E) ON SOLIDS

Recent progress in the application of the (e,2e) technique for elucida ting the electronic structure of condensed matter is discussed. Partic ular emphasis is given to the description of a new third generation el ectron momentum spectrometer, which operates with an incident beam ene rgy of 20-30 keV, uses asymmetric non-coplanar scattering kinematics w ith scattered electrons emerging at polar angles theta(s) = 14-degrees , and the ejected electrons emitted at phi(e) = 76-degrees. A range of scattered and ejected electron energies (20eV) and azimuthal angles ( -18-degrees less-than-or-equal-to phi(s) less-than-or-equal-to 18-degr ees,-7-degrees less-than-or-equal-to phi(e) - pi less-than-or-equal-to 7-degrees are detected in parallel by means of two-dimensional positi on sensitive detectors. Software determines the energies and angles of the detected electrons, corrects for flight times through the analyse rs, and determines the separation energy and momentum for each event. With a 5nm amorphous carbon membrane, the true signal rate is 6Hz and the signal to background ratio is 1 with an incident current of 100nA. Without monocromation of the incident beam the energy resolution is 1 eV and the momentum resolution is 0.15au. The spectral momentum densit ies obtained for evaporated amorphous carbon are compared with theoret ical results.