Many difficult technological problems encountered in fusion reactors could probably be solved if D-3He fuel would be used instead of D-T fuel. The paper examines the burn characteristics for inertial confinement fuel pellets, i.e. for pure D-3He fuel pellets and for D-3 ignitor/D-3He fuel pellets, using a hydrodynamics code modified to include neutron transport and charged particle transport. The results indicate that it is difficult to ignite pure D-3He fuel pellets with a reasonable driver energy. However, the ignition conditions can be relaxed by using D-T fuel as ignitor. It is found that a fuel gain of ∼480 can be obtained with D-T/D-3He pellets having a spark temperature of 5 keV, a D-T ignitor ρR value of 3.0 g/cm2 and a total fuel ρR value of 15.5 g/cm2. When the density of these pellets is assumed to be 10 000 times the liquid density, the internal energy of the configuration at ignition is ∼1.2 MJ, which is still more severe than that in the case of D-T fuel. It is also shown that the transport of 14.7 MeV protons produced by the D-3He reaction plays a significant role in determining the burn characteristics of the pellets. Nuclear elastic scattering (NES) of 14.7 MeV protons enhances the ion heating, leading to a fuel gain which is higher by about 20% than that in the case without NES. The effect of nuclear spin polarization is also examined for an ideally polarized fuel pellet. It is found that the burn characteristics are improved and that the required driver energy is possibly decreased.
Particle fueling experiments with a series of pellets in LHD