SELF-GENERATED MAGNETIC-FIELD IN CO2-LASER-PRODUCED PLASMA

Measurements have been made of an azimuthal magnetic field spontaneously associated with plasma produced by the irradiation of a CD2 target by an 80-ns CO2-laser pulse. The magnetic field diffuses from an initial source into an ambient nitrogen plasma. Extrapolation of measured data to the initial target surface shows a field intensity of ∼0.6 MG. The diffusion coefficient calculated from the ambient plasma parameters is in accordance with direct experimental data. The diffused field is followed by the expanding laser target plasma. For sufficiently high ambient gas pressure, the field direction is reversed.