Spatial-temporal distribution of magnetic fields in laser plasmas

An experimental and theoretical analysis is made of the structure of magnetic fields generated by a laser plasma formed by irradiating solid targets with pulsed radiation of moderate intensity. It is shown that the temporal shape of the magnetic field pulses is practically independent of the radiation energy, but is to a large extent determined by the position of a measuring sensor. As the distance from the focal spot is increased, the temporal characteristics of the field become stronger. The target conductivity influences the spatial distribution of the magnetic fields. The dependences are found of the maximum amplitude of the magnetic fields outside and inside closed shells on the pressure of the medium surrounding the target and on the diameter of the focal spot.