Electron energy loss spectroscopy with parallel readout of energy and   momentum
  We introduce a high energy resolution electron source that matches the requirements for parallel readout of energy and momentum of modern hemispherical electron energy analyzers. The system is designed as an add-on device to typical photoemission chambers. Due to the multiplex gain, a complete phonon dispersion of a Cu(111) surface was measured in seven minutes with 4 meV energy resolution. 
Harald Ibach and Fran\c{c}ois C. Bocquet and Jessica Sforzini and   Serguei Soubatch and F. Stefan Tautz
physics.ins-det