The effects of initial electron velocities and space charge in secondary emission

This paper treats a secondary emitter as a fixed-temperature thermionic emitter with an equivalent work function which depends for its value upon the current density of the incident primary electrons. This permits Langmuir´s treatment of the parallel-plane thermionic diode to be applied to secondary emission. The resulting equations account quantitatively for observed secondary-emission effects caused by space charge and initial electron velocities. The paper concludes with a discussion of three specific electron devices in which secondary-emission effects due to space-charge and initial electron velocity are important.