Generation of a magnetic field by a laser jet plasma at low laser radiation densities

Measurements were made of the components of a magnetic field resulting from irradiation of aluminum and copper targets with neodymium laser pulses of microsecond duration and 4×10⁷ – 2×10⁹ W/cm² intensities. The pressure of the surrounding air was varied from 5×10^–2 to 160 Torr. The dependences of the magnetic field on the distance from the center of the illuminated spot, pressure of the surrounding air, and laser radiation intensity were determined experimentally. A considerable increase in the magnetic field in the case of irradiation of plane targets with crossed and inclined laser beams indicated that the field was due to those regions of a plasma jet where the electron temperature and electron density gradients were not collinear.