Dose Course 2018_Flipping book

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Electron transport

❑ When studying electron transport, there are a very large number of interactions taking place when an electron is slowing down. A lot of secondary electrons are also produced during the interactions. ❑ It would take a very long time to simulate all these events. Instead the electron’s case history is sampled at different “traveling” points. ❑ This condensed case history, which gives a macroscopic picture of the process, takes in each step into account several collisions. ❑ To minimize the Monte Carlo calculation time the number of steps should be as few as possible. ❑ Of great importance is also that the smaller the step size is, the smaller the net angular deflection and the energy loss are from one step to the next. ❑ The multiple scattering theories become applicable. When dealing with interactions close to interfaces a small step size is preferable. A large step size leads to a larger uncertainty.

Dublin 2018