The axial distribution of energy deposited in bremsstrahlung conversion targets is modelled using the Monte Carlo N -Particle (MCNP) code. Systems comprising a disc-shaped target, segmented axially, and a point source of paraxial, monoenergetic electrons (2, 7, 10, or 14 MeV) are considered. Thick tantalum and aluminium targets and also tantalum targets of optimum thickness are modelled. Energy...