Two-Dimensional Distribution of Self-Generated Magnetic Fields near the Laser-Plasma Resonant-Interaction Region

The two-dimensional distribution of self-generated magnetic fields near the laser-plasma interaction region is observed for the first time by the very simple method of laser irradiation of audio magnetic tape. The lobe structure is a maximum at the incident angle of 10° to 15° for $p$-polarized laser light. The direction of the fields is perpendicular to the density gradient and to the incident $p$-polarization plane. These observations support resonance absorption as the field-generation mechanism.