Transverse interferometry of a hydrogen-filled capillary discharge waveguide

Transverse interferometric measurements are presented of the plasma channel formed in a H-filled capillary discharge waveguide recently used to generate 1 GeV electrons in a laser-driven plasma accelerator for the 1st time. The measurements are in good agreement with nonlocal thermal equil. simulations, but showed significant differences with the results of a quasistatic model developed by Bobrova et al. [Phys. Rev. E. 65, 016407(2001)]. The measurements are used to det. scaling laws for the axial electron d. and matched spot size of the plasma channel, enabling optimization of the channel to specific applications. [on SciFinder (R)]