Fast ion dynamics measured by collective Thomson scattering

Magnetically confined fusion plasmas contain highly non-thermal populations of fast ions resulting from fusion reactions and plasma heating. With energies in the MeV range, two to three orders of magnitude above the bulk ion and electron energies, the fast ions typically carry 1/3 of the plasma kinetic energy and even more of the free energy. It is essential that these energetic ions remain confined while they slow down and heat the thermal bulk plasma.