Critical-Voltage Effects in Electron-Channeling Patterns

Abstract
A linewidth minimum in the (220) electron-channeling-pattern (ECP) reflection in tungsten has been measured at 10.50±0.05 keV incident beam energy. This is interpreted as a second-order critical-voltage effect and is the first reported observation of such an effect in ECP's. The experimental critical voltage has been used to refine the tungsten (110) Fourier lattice-potential coefficient. The shape of the line-narrowing curve is used to estimate the depth of ECP information.