The role of the temperature anisotropy in the deuterium-tritium fuel ignition under the effect of relativistic shock waves

This paper investigates the influence of temperature anisotropy on the ignition criterion of deuterium-tritium fuel in fast ignition fusion schemes that rely on short-pulse lasers-generated shock waves. The results show that increasing the temperature anisotropy parameter, β = T⊥/T∥, unexpectedly increases the fraction of alpha particles created and deposited into the ignition domain. For β 1, the maximum confinement parameter remains below 4 g/cm2, whereas for β 1, it exceeds 4 g/cm2. The fusion energy fraction, fα, decreases throughout the laser pulse irradiation of the fuel (1 picosecond). A 100-fold increase in the temperature anisotropy parameter, β, leads to a 38% increase in the required plasma density times the hot spot dimension for fuel ignition. However, for β less than 1, the fusion energy fraction deposited decreases with time and reaches its minimum value of about 0.1 at the end of the laser pulse.