Figure 3.

The absorbed-dose energy dependence of a normal EBT film (with a surface layer thickness of 6 μm) as well as a modified film where the surface layer thickness is 8 μm. Also included is the absorbed-dose energy dependence at 50 keV of a hypothetical film, where the only layer that is not composed of water is the surface layer (only surface), a hypothetical film that is normal except that the surface layer is composed of water (no surface) as well as only active and no active from Fig. 2. The uncertainties for the hypothetical film data points are smaller than the symbols.