  Recent implosion experiments performed at the OMEGA laser facility reported
by Casey et al.[1], displayed an anomalously low dd proton yield and a high tt
neutron yield as compared to dt fusion reactions, explained as a stratification
of the fuel in the implosion core. We suggest that in the com- pression stage
the fuel is out of equilibrium. Ions are inward accelerated to a velocity v0
independent on the particle type. Yield ratios are simply given by the ratios
of fusion cross-sections obtained at the same velocity. A 'Hubble' type model
gives also a reasonable description of the data. These considerations might be
relevant for implosion experiments at the National Ignition Facility as well.
