Influence of the mixing of Au with D and T upon alpha heating in hot dense plasmas

Abstract

The influence of the mixing of Au with D and T (DT) upon alpha heating is studied in the wide ranges of plasma temperatures from 0.1 to 100.0 keV, under the assumption that all the charged particles in the mixture are in the same temperature. Two cases of mixture densities 4.15 and 415 g/cc are discussed, where the average ionization degree of Au ions and the partial densities of different ions in the mixture are determined by the average atom model. It is found that the mixing decreases the energy partition fraction for DT ions significantly even if the number of Au ions is 1.0% of that for DT ions. The mixing also lengthens the range of alpha particles in the plasmas, which is more prominent when Au ion is in a low ionized state. Moreover, the heating of Au ions by alpha particles is found much easier than that of DT ion All these are very harmful to the controlled fusion. All the results about energy partition fractions are mainly because that the heavy Au ion is usually in a highly charged state in the plasmas. This makes the nuclear stopping due to Au ions much bigger than that due to DT ions and cover the incident energy range for the heating of DT ions by alpha particles. The similar work in Phys. Plasmas 21,102,307 (2014) is found doubtful since its nuclear stopping due to high Z ions was obtained by means of perturbation theory.