In: Physics
(from Reif, Chapter 12, problem 5)
The total scattering cross section for an electron-air molecule collision is about 10^(-15)cm^2
At what gas pressure will 90 percent of the electrons emitted from a cathode reach an
anode 20 cm away? (Assume that any electron scattered out of the beam does not reach
the anode; i.e. neglect multiple scattering.)