Abstract: A laser-plasma-based acceleration system includes a focusing element and a laser pulse emission directing a laser beam to the focusing element to such that laser pulses transform into a focused beam and a chamber defining a nozzle having a throat and an exit orifice, emitting a critical density range gas jet from the exit orifice for laser wavelengths ranging from ultraviolet to the mid-infrared. the critical density range gas jet intersects the focused beam at an angle and in proximity to the exit orifice of the nozzle to define a point of intersection between the focused beam and the critical density range gas jet. In intersection with the critical density range gas jet, the pulsed focused beam drives a laser plasma wakefield relativistic electron beam. A corresponding method of laser-plasma-based acceleration is also described. The critical density range may include 2×1020 cm?3 to 5×1021 cm?3.

Abstract: A laser-plasma-based acceleration system includes a focusing element and a laser pulse emission directing a laser beam to the focusing element to such that laser pulses transform into a focused beam and a chamber defining a nozzle having a throat and an exit orifice, emitting a critical density range gas jet from the exit orifice for laser wavelengths ranging from ultraviolet to the mid-infrared. the critical density range gas jet intersects the focused beam at an angle and in proximity to the exit orifice of the nozzle to define a point of intersection between the focused beam and the critical density range gas jet. In intersection with the critical density range gas jet, the pulsed focused beam drives a laser plasma wakefield relativistic electron beam. A corresponding method of laser-plasma-based acceleration is also described. The critical density range may include 2×1020 cm?3 to 5×1021 cm?3.

Abstract: Nonlinear absorption of a sub-picosecond laser pulse is used to generate one or more spatially elongated heated gas volumes. Transient density variations caused by the spatially elongated heated gas volumes provide a refractive index profile capable of guiding electromagnetic radiation through the gas. The waveguide structure in the gas is disposed between the spatially elongated heated gas volumes and results from interaction between acoustic waves generated by the spatially elongated heated gas volumes or from a non-uniform thermal gas profile caused by the spatially elongated heated gas volumes. The nonlinear absorption can be repeated at regular intervals in time and space to renew the waveguide in the gas, thereby allowing for the guiding of high average power radiation (e.g., megawatts) that is well below self-focusing or stimulated Raman scattering thresholds.