It is shown that the measurements of Edwards et al. do not demonstrate the existence of two independent self-generated magnetic fields in the laser-target interaction region. On the contrary, these results illustrate, once more, the two-phase expansion of the magnetic fields spatial configuration: diffusion within the photoionized background followed by convection with the laser plasma.

• Received 30 January 1978

DOI:https://doi.org/10.1103/PhysRevA.19.408