Space Charge - Shot Noise

Shot Noise

Space charge tends to reduce shot noise. Shot noise results from the random arrivals of discrete charge; the statistical variation in the arrivals produces shot noise. A space charge develops a potential that slows the carriers down. For example, an electron approaching a cloud of other electrons will slow down due to the repulsive force. The slowing carriers also increases the space charge density and resulting potential. In addition, the potential developed by the space charge can reduce the number of carriers emitted. When the space charge limits the current, the random arrivals of the carriers are smoothed out; the reduced variation results in less shot noise.