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Yun, Bob H.

Physics

1970

MS

Equations for photoemission current are developed, taking in account the distribution of initial velocities of the photoelectrons. Only the velocity components normal to the emitter surface are considered, in keeping with an assumed one-dimensional variation of potential between infinite parallel-plane electrodes. The electron energy distribution in the metal is assumed to be given by the Fermi-Dirac distribution evaluated at temperature T=0°K. The Foler formulation of photoemission is used. In this application Poisson's equation cannot be solved in closed form; numerical solutions, however, are presented. The solutions consist of curves and tables from which current-voltage relationship for a given set of experimental parameters can be readily obtained. Assuming the Fowler conditions for photoemission are satisfied, the criteria for a space-charge limited situation can be readily discerned by inspection of the curves and tables presented in this paper.