Laser Wakefield in Low Density Plasma

The laser wakefiled (LWF) and the relativistic and charge-displacement self-channeling in the comparatively low density plasma were studied. The dynamics of the electron plasma wave (EPW) in LWF was experimentally observed at the electron density of ∼10 16 cm -3 . The two dimensional instantaneous image of EPW was also obtained. The asymmetric 2D image was explained by the modified liner theory. These experimental results suggest that the intensity of ∼10 18 W/cm 2 was achieved in the low density static gas target. This means the possibility of not only the coherent control of EPW, but also the long relativistic and charge-displacement self-channeling with the low density static gas. For the self-channeling, the simple model tells us that the long channel without defocusing could be possible with a tens of TW, ps glass laser system.