  Ablative Rayleigh-Taylor instability growth was investigated to elucidate the
fundamental physics of thermal conduction suppression in a magnetic field.
Experiments found that unstable modulation growth is faster in an external
magnetic field. This result was reproduced by a magnetohydrodynamic simulation
based on a Braginskii model of electron thermal transport. An external magnetic
field reduces the electron thermal conduction across the magnetic field lines
because the Larmor radius of the thermal electrons in the field is much shorter
than the temperature scale length. Thermal conduction suppression leads to
spatially nonuniform pressure and reduced thermal ablative stabilization, which
in turn increases the growth of ablative Rayleigh-Taylor instability.
