Energy Deposition Distributions

The distribution in the increments to the energy deposited in a small site as a result of the interaction of a primary charged particle with a molecule of the medium varies with the position of the molecule along the track of the particle. It is shown that, nevertheless, the energy deposited in the site can be treated as though it were the result of a compound-Poisson process based on a single, effective distribution in the increments due to individual interactions regardless of the position of the interaction along the track. An expression for the effective distribution is given. The theory is generalized to quantities other than energy deposition.