Editing Field electron emission (section)

=== Field electron spectroscopy (electron energy analysis) ===
Energy distribution measurements of field-emitted electrons were first reported in 1939.<ref name=AH39/> In 1959 it was realized theoretically by Young,<ref name=Y59>{{cite journal|doi=10.1103/PhysRev.113.110|title=Theoretical Total-Energy Distribution of Field-Emitted Electrons|year=1959|last1=Young|first1=Russell D.|journal=Physical Review|volume=113|issue=1|pages=110–114|bibcode = 1959PhRv..113..110Y }}</ref> and confirmed experimentally by Young and Mueller<ref name=YM59>{{cite journal|doi=10.1103/PhysRev.113.115|title=Experimental Measurement of the Total-Energy Distribution of Field-Emitted Electrons|year=1959|last1=Young|first1=Russell D.|last2=Müller|first2=Erwin W.|journal=Physical Review|volume=113|issue=1|pages=115–120|bibcode = 1959PhRv..113..115Y }}</ref> that the quantity measured in spherical geometry was the distribution of the total energy of the emitted electron (its "total energy distribution"). This is because, in spherical geometry, the electrons move in such a fashion that [[angular momentum]] about a point in the emitter is very nearly conserved. Hence any [[kinetic energy]] that, at emission, is in a direction parallel to the emitter surface gets converted into energy associated with the radial direction of motion. So what gets measured in an energy analyzer is the [[total energy]] at emission.

With the development of sensitive electron energy analyzers in the 1960s, it became possible to measure fine details of the total energy distribution. These reflect fine details of the [[surface physics]], and the technique of Field Electron Spectroscopy flourished for a while, before being superseded by newer surface-science techniques.<ref name=mo84>{{cite book|author=A. Modinos|title=Field, Thermionic and Secondary Electron Emission Spectroscopy|publisher=Plenum, New York|year=1984|isbn=0-306-41321-3}}</ref><ref name=GP73>{{cite journal|doi=10.1103/RevModPhys.45.487|title=Field Emission Energy Distribution (FEED)|year=1973|last1=Gadzuk|first1=J. W.|last2=Plummer|first2=E. W.|journal=Reviews of Modern Physics|volume=45|pages=487–548|bibcode=1973RvMP...45..487G|issue=3}}</ref>