a. How many ion pairs are produced in 1 cm3 of air during an exposure of 100 mR? The density of air at STP is ρ = 1:293kg m-3. What is the absorded dose to air?
b. An thin walled carbon-wall ionization chamber, whose volume is 2 cm3, is filled with standard air at 0°C and 760 mmHg and is placed inside a tank of water to make a depth-dose measurement. A 25 MeV electron beam produces a current of 0.02 μA in the chamber. If the mass stopping power of water at the depth of measurement for 25 MeV electrons relative to air is 1.068, what is the dose?