Plasma jet formation and magnetic-field generation in the intense laser plasma under oblique incidence

Long-scale jet-like x-ray emission was observed in the experiments on the i nteractions of 100 TW laser light with plasmas. The jet formation is invest igated by simulations with a two-dimensional particle code. When an S-polar ized intense laser is irradiated obliquely on an overdense plasma, collimat ed MeV electrons are observed from the critical surface in the specular ref lection direction. These electrons are found to be accelerated through the coronal plasma by the reflected laser light, which was modulated at the ref lection point. The quasisteady magnetic channel occurs simultaneously and c ollimates the energetic electrons along the specular direction. In the case of P-polarized laser, it is found that an outgoing electron stream is indu ced at the critical surface due to Brunel mechanism. Megagauss quasistatic magnetic fields are generated and pinch the electron stream. The angle of e jected electron depends on the electron's energy. The emission direction of the jet generated by the P-polarized light is determined by the canonical momentum conservation along the target surface. (C) 1999 American Institute of Physics. [S1070-664X(99)03207-3].