摘要
Straight plasma channels are widely used to guide relativistic intense laser pulses over several Rayleigh lengths for laser wakefield acceleration.Recently,a curved plasma channel with gradually varied curvature was suggested to guide a fresh intense laser pulse and merge it into a straight channel for staged wakefield acceleration[Phys.Rev.Lett.120,154801(2018)].In this work,we report the generation of such a curved plasma channel from a discharged capillary.Both longitudinal and transverse density distributions of the plasma inside the channel were diagnosed by analyzing the discharging spectroscopy.Effects of the gas-filling mode,back pressure and discharging voltage on the plasma density distribution inside the specially designed capillary are studied.Experiments show that a longitudinally uniform and transversely parabolic plasma channel with a maximum channel depth of 47.5µm and length of 3 cm can be produced,which is temporally stable enough for laser guiding.Using such a plasma channel,a laser pulse with duration of 30 fs has been successfully guided along the channel with the propagation direction bent by 10.4◦.
基金
This work was supported by the National Natural Science Foundation of China(Grant Nos.11991074 and 12225505)
the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA25010500,XDA25050000 and XDA17040504).
