Equation 20.3 is the mean free path of a particle through a gas of identical particles of equal radius. An electron can be thought of as a point particle with zero radius.
a. Find an expression for the mean free path of an electron through a gas.
b. Electrons travel 3 km through the Stanford Linear Accelerator.
In order for scattering losses to be negligible, the pressure inside the accelerator tube must be reduced to the point where the mean free path is at least 50 km. What is the maximum possible pressure inside the accelerator tube, assuming T = 20°C? Give your answer in both Pa and atm.