Spatial distribution of the plasma temperature under ion-beam fast ignition

Results are presented from theoretical studies of the formation of the spatial temperature distribution in plasma heated by a high-energy ion beam under the conditions in which the free path lengths of ions of different parts of the beam in plasma varies in the course of its heating. Special attention is paid to ionbeam heating of deuterium-tritium (DT) plasma under the conditions of fast ignition of inertial confinement fusion (ICF) targets. The influence of the initial energy spectrum of the heating beam ions on the spatial temperature distribution is investigated. For beams with different ion charges, masses, and initial energy spectra, criteria are determined for the formation of different types of spatial temperature distributions, namely, a distribution with a negative temperature gradient and a quasi-uniform distribution, which correspond to the edge ignition of a precompressed ICF target, as well as a distribution with a temperature peak, which corresponds to the ignition in the inner region of the target.