GENERATION OF PICOSECOND HARD X-RAYS BY TERA WATT LASER FOCUSING ON ACOPPER TARGET

Hard x-ray generation from tera-watt laser irradiation (4 TW, 42 fs at 780 nm) on a solid copper target has been studied in a range of the l aser-power density between 3 x 10(16) and 2 x 10(17) W/cm(2). Short-pu lsed x rays are generated within 6.4 ps and include Cu K-alpha and K-b eta line emissions and a continuum between 3 and 6 keV. The maximum in tensity of Cu K-alpha radiation has been estimated to be 6.5 x 10(10) photons (4 pi sr pulse)(-1). The mechanism of hard x-ray generation ha s been discussed. (C) 1998 American Institute of Physics. [S0003-6951( 98)00543-9].