Fig. 9.

Images showing the effects at different incident electron energies of both electron backscattering from the metal film holder and from light generated within the plastic film backing due to the passage of high energy electrons in Kodak SO-163 film. (a) Photograph of a film holder showing the cut-away region in the centre. The area where black ink was applied to the back of the sheet of film to suppress light reflection is indicated by the dashed box. (b) Image taken with 120 keV electrons showing the area around the cut-away film holder. The OD in the area where the ink was applied is $\sim 2\%$ lower (the developed film is lighter in the area where the ink was applied). At 120 keV there is no sign of any effects from the film holder. (c) Image taken with 200 keV electrons showing a reduction in OD of $\sim 9\%$ with the ink and a $\sim 4\%$ reduction where there is no film holder and so no electron backscatter from the film holder. (d) Image taken with 300 keV electrons showing a $\sim 10\%$ reduction in OD with the ink and a $\sim 15\%$ reduction in OD from the removal of electron backscatter.