A Fitting Formula For Electron-Ion Energy Partition Fraction Of 3.54-Mev Fusion Alpha Particles In Hot Dense Deuterium-Tritium Plasmas*

Based on our previous work (Phys. Plasmas 25 012704 (2018)), a fitting formula is given for electron-ion energy partition fraction of 3.54-MeV fusion alpha particles in deuterium-tritium (DT) plasmas as a function of plasma mass density rho, electron temperature T-e, and ion temperature T-i. The formula can be used in a huge range of the plasma state, where rho varies between 1.0 g/cc similar to 10.0(3) g/cc and both T-e and T-i change from 0.1 keV to 100.0 keV. Relativistic effect for electrons is investigated including the effect of the projectile recoil in the plasmas at T-e >= 50.0 keV. The partition fraction for T-e > T-i is found to be close to that for T-e = T-i. The comparisons with other fitting results are made at some plasma densities when T-e = T-i, and the difference is explained. The fitting result is very close to the calculated one in most cases, which is convenient for the simulation of alpha heating in hot dense DT plasmas for inertial confined fusion.