Evolution of the Radiative Thermal Instability in a Confined Medium

Thermally unstable fluid tends to self-arrange into clouds of hot or cold material, which are internally uniform and separated by thin conduction fronts. Solutions are derived for the evolution of these clouds while accounting, unlike most previous works, for both time-varying pressure and interactions between conduction fronts. Interfront interactions fundamentally alter the dynamics at late times. New stable configurations and secondary instabilities are demonstrated, which may be relevant to fusion plasmas and to the study of photoionized plasma in the laboratory.