On a possibility of condensed matter surface profiling by a high brightness electron probes

In the present work the phenomenon of ablation is treated as a fast process of phase bound-free transition in excited or ionized structural elements (atoms, molecules) of condensed substance exposed to intense corpuscular radiation, in particular, intense electron fluxes. It is known that interaction of a substance with intense either laser or electron beams exhibits some common regular features, which have not yet been interpreted unambiguously. These are the following. 1. The phenomena of laser and electron ablation are of threshold nature, i.e., they appear only when the beam intensity or the electron flux power density (P) exceeds some threshold value (P₁) characteristic of a given substance. For a wide range of condensed media, P₁ ≈ 50 MW/cm² [3]. 2. There is a finite time delay (Δt) between the onset of the substance exposure to a concentrated energy flux and the moment of phase transition of the substance to plasma. The time Δt strongly depends on the P level and can widely vary from ≈ 10^-8 s ( P ≥ P₁) to ≈ 10^-13 s (at P ≫ P₁) [1,3].