Energy deposition and heat transfer in a pulse-heated field emission tip at high repetition rates

Abstract

Abstract This article explores the possibility of achieving high repetition rates for evaporation of atoms from a field emission tip. An investigation of the heat transfer process in a typical field emission tip is presented. Numerical integration using an alternate direction method and volume heating was used. The results indicate that the heat transfer process in a tip of a paraboloid shape can be approximated well to a one-dimensional conduction problem. The calculations show that a power density of at least 10 18 W/m 3 must be delivered into tip volumes on the order of 10 −20 m 3 in order to achieve 10 6 pulses per second with an evaporation pulse width of less than 1 ns. Monte Carlo calculations show that an electron beam will deposit a peak amount of energy on the order of 1–5 keV per electron for an incident energy in the range of 3–25 keV and the amount of deposited energy will decrease continuously with increasing incident energy.