Hot-electron energy deposition around unsupported laser targets

Free-falling spheres, released by a simple mechanism, are used as laser targets. Hot-electron energy transport upon one-sided irradiation with 300-ps iodine laser pulses (6×1015 W cm−2) is studied by various methods, including x-ray pinhole photography and time-resolved shadowgraphy. Spatial energy deposition is consistent with hot-electron spreading in the presence of self-generated magnetic fields, as suggested by recent experiments and simulations. The insensitivity of the results to the presence of a supporting stalk is attributed to inductive decoupling of the target. Free-falling targets open the possibility of highly symmetric implosion experiments.