Fast ignition schemes for inertial confinement fusion

The, controlled production of a local hot spot in supercompressed deuterium + tritium fuel is examined in details. Relativistic electron beams (REB) in the MeV and proton beams in the few tens MeV energy range produced by PW lasers are respectively considered. A strong emphasis is given to the propagation issues encountered by the gradients of the outer core of compressed fuel. A specific attention is paid the final and complete particle stopping resulting in hot spot generation as well as to the interplay of collective vs particle stopping at the entrance channel on the low density side in plasma target. In this respect electromagnetic instabilities are given a lot of scrutiny. Relevant parameters are transverse beam and plasma temperatures as well as densities ratio of target electrons to beam particles. Proton beams are demonstrated totally enaffected by the Weibel instability. Moreover, REB production and fast acceleration mechanisms are also given their due attention. Proton fast ignition looks promising.