Influence of electron beam intensity

There are some very beam-sensitive materials that show strong damaging effects under electron beam irradiation. An example is gelatin, which shows void formation due to evaporation of some material portions. In such a material, one can draw with a focused electron beam a pattern in the material see Fig. 1.64. The electron beam path is marked by small voids in the material. 

On the other hand, an electron beam can initiate processes in the polymeric material that yield an increase in material contrast. Spherulites with a radial arrangement of lamellae have been made clearly visible in an HEM micrograph in Fig. 1.65 through the use of irradiation-induced contrast enhancement. Similar effects of contrast enhancement can be used in polyethylenes (see Fig. 1.9 and Figs. 2.69, 2.70) [1,5]. 

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