Effect of gold doping on relativistic electron beam transport in high-density plasma

We investigate the influence of gold doping on the transport range of a relativistic electron beam in high-density deuterium–tritium (DT) fuel, which could be encountered in the double-cone ignition laser fusion. We develop the stopping power model to include gold doping and then analyze the influence of Coulomb collision and bremsstrahlung on the electron transport range with different gold doping ratios, consistent with the Geant4 simulations. When the gold doping ratio increases from 0.5% to 30%, the transport range of a 10 MeV electron beam is decreased by 9.6% and 18.5% via the bremsstrahlung. For the 1 MeV beam, the decrease of the range becomes 0.7% and 1.0%. We also investigate the transverse broadening of the electron beam and radiated photon energy reabsorption in a spherical target. When the gold doping ratio is 2% and the beam energy is increased from 1 MeV to 5 MeV, the bremsstrahlung photons cover 2.6% to 10.3% of the total beam energy. Meanwhile, the reabsorbed photon energy is reduced from 31.6% to 8.9%.