A layer of water 1 mm thick between two equilibrium-thickness layers of Teflon is irradiated by 2-MeV photons. (a) From Burlin theory calculate the approximate average dose in the water (EWaitfc thre) collision kerma in the adjacent Teflon is 10 Gy. Take pen/ p = 0.0225 cm2/g for Teflon, use Eq. (10.47) as amended by Janssens et al. (1974) to obtain 0, assume a diffuse electron field, and neglect y-ray attenuation. -W hat are the small-cavity (B-G) and large-cavity limiting values for DW,,,,?