Using a current method for measuring ion-induced electron emission from LiF

The interaction of ions with an insulating substrate leads to surface charging. For intense ion beams these charges are not sufficiently fast removed between successive ion impact events. As a result the trajectories of the incident beam and the electron emission yield may be altered in a hardly predictable way. We demonstrate, that by heating an alkali-halide sample to a sufficiently high temperature, this macroscopic charging can be avoided and a simple current method can be used to study electron emission from such a surface. Measured electron emission yields from a LiF(1 0 0) single crystal due to impact of singly and multiply charged heavy noble gas ions (argon and xenon) are presented. For argon projectiles our results compare well with previous data, which were obtained using a more sophisticated electron statistics method and six orders of magnitude less intense ion beams.