Scattering losses of a charged particle beam from a preformed channel

In charged particle beam-pellet fusion, the intense beam is guided to the target through a gaseous channel that might be several meters long. The efficiency with which energy is delivered to the target is determined to a great extent by the interactions of such a beam with the channel; chief among these is scattering. A Monte Carlo code that allows tor Coulomb and neutral scattering was used to determine the losses from an intense electron beam in a cylindrical channel. It is shown that a 1-cm-radius, 90-keV beam in a hydrogen channel of the same radius, 50-cm-long with a density of 10¹⁴cm⁻³ and a temperature of 1/2 eV will not traverse such a channel when the ionization is much below 20%. The spatial and energy distributions of the scattered beam particles are also examined.