Spin and energy analyzed photoemission: A feasibility analysis

New scientific opportunities, particularly for investigation of surface magnetism, will be provided by spin and energy analyzed photoemission. Electron‐optical conservation laws and phase space concepts are summarized and applied to determine the feasiblity of an experiment consisting of a photoemitter in a magnetic field, a photoelectron energy analyzer and an electron spin analyzer. For the example of photoemission from a Ni crystal using He I resonance radiation and typical parameters for the energy and spin analyzers, a final signal count rate of approximately 220 counts/s is calculated. Ways to increase the count rate by orders of magnitude are described. In particular, a new experimental configuration is suggested which may avoid the large reduction in count rate caused by the magnetic field.