OBSERVATION OF THE PRE-EXPLOSION STATE AND OF THE INITIAL MOMENT OF AN EXPLOSION OF A FIELD-EMISSION CENTER IN A FIELD-EMISSION MICROSCOPE

Never-before-observed emission images corresponding to a transition fr om intense field emission to explosive electron emission are obtained in a Muller field emission microscope with short (similar to 2 ns) hig h-voltage pulses. These images are much brighter than ordinary field e mission images. Moreover, the images have a characteristic multi-brigh tness structure with ring-shaped frames around regions of different br ightness. Analysis of the experimental data points to a field emission nature of these images. The appearance of such emission images can be explained by emission from a liquid phase which arises immediately pr ior to the explosion of a microemitter. (C) 1998 American Institute of Physics.