  Because of the large mass differences between electrons and ions, the heat
diffusion in electron-ion plasmas exhibits more complex behavior than simple
heat diffusion found in typical gas mixtures. In particular, heat is diffused
in two distinct, but coupled, channels. Conventional single fluid models
neglect the resulting complexity, and can often inaccurately interpret the
results of heat pulse experiments. However, by recognizing the sensitivity of
the electron temperature evolution to the ion diffusivity, not only can
previous experiments be interpreted correctly, but informative simultaneous
measurements can be made of both ion and electron heat channels.
