Constraints on ion velocity distributions from fusion product spectroscopy

Abstract Recent inertial confinement fusion experiments have shown primary spectral moments which are incompatible with a Maxwellian velocity distribution description. These results show that an ion kinetic description of the reacting ions is necessary. We develop theoretical classification non-Maxwellian distributions using moments. At mesoscopic level, monoenergetic decomposition reveals there constraints on space accessible by isotropic distributions. General expressions for directionally dependent anisotropic derived. macroscopic fluid element velocities modifies in constrained manner. Experimental observations can be compared to these identify character and isotropy underlying reactant determine if plasma hydrodynamic or kinetic.