Tapered capillaries applied in laser wakefield acceleration

Summary form only given. The gas-filled capillary discharge waveguide (CDW) is a commonly applied accelerating structure for the laser wakefield accelerator (LWFA) because an intense femtosecond laser pulse can be successfully guided over several centimetres, leading to the generation of GeV-scale electron beams. Simulations have shown that tapering the longitudinal plasma density leads to significant enhancement of the final electron energy in a single accelerating stage.