Energy deposition and deflection of α particles in hot dense plasmas relevant to inertial confinement fusions

Abstract

Based on the kinetic theory, improved T -matrix models for the continuous-slowing-down and the linear-energy-transfer stopping powers are established at the same level, where multiple scattering effects and the related transverse deflection are accounted for consistently and systematically. The degree of deflection characterizing the extent of transverse deflection is defined by means of the ratio of these two stopping powers. Calculations for the energy deposition and deflection of α particles in hot dense deuterium–tritium (DT) plasmas and also in hot dense DT plasmas mixed with carbon (C) impurities are performed. Multiple scattering effects and the resulting transverse deflection are demonstrated to have a significant influence on the stopping power of α particles, in particular, in mixtures containing different ions with large mass and charge asymmetry. It is shown that for DT plasma mixed with $5\%$ C impurities, the range and penetration depth of the α particle are shortened by about $21\%$ and $27\%$ , respectively. Our models are found to be appropriate for the evaluation of stopping powers not only in weakly coupled plasmas but also in moderately degenerate and correlated plasmas. These results manifest that multiple scattering effects and the induced transverse deflection need to be taken into account in modeling the transport of α particles in hot dense plasmas relevant to inertial confinement fusion.

Keywords

• stopping power
• deflection of α particles
• deuterium–tritium plasmas
• inertial confinement fusion
• quantum kinetic theory
• energy deposition