  A completely rigorous first-principles calculation of the charged particle
stopping power has recently been performed by Brown, Preston, and Singleton
(BPS). This calculation is exact to leading and next-to-leading order in the
plasma number density, including an exact treatment of two-body quantum
scattering. The BPS calculation is therefore extremely accurate in the plasma
regime realized during the ignition and burn of an inertial confinement fusion
capsule. For deuterium-tritium fusion, the 3.5 MeV alpha particle range tends
to be 20-30% longer than most models in the literature have predicted, and the
energy deposition into the ions tends to be smaller. Preliminary numerical
simulations indicate that this increases the rho-R required to achieve
ignition.
