Application of fast imploding capillary discharge for laser wakefield acceleration

A new method of optical guiding for the laser wakefield acceleration using an imploding phase of a gas-filled fast capillary discharge has been proposed. An imploding plasma column has a concave electron density profile in the radial direction just before a stagnation phase driven by a converging current sheet and shock wave. The feasibility of optical guiding of high intensity laser pulses using an imploding phase of the fast capillary discharge has been experimentally demonstrated over a distance of 2 cm corresponding to ~12.5 times the Rayleigh length. A high intensity laser pulse (>10 ¹⁷ W/cm²) focused on the front edge of the capillary has propagated through the center of the column maintaining its spot size. The electron density in the fully ionized channel is estimated to be 6.0×10¹⁶ cm^-3 on the axis and 1.5×10¹⁸ cm^-3 on the peaks with the diameter of 70 μm