2020/08/31 by A. Picksley, A. Alejo, R. J. Shalloo +9 · 1 citation
Physics and Astronomy · #physics.acc-ph #physics.plasm-ph
paper · pdf · doi:10.1103/physreve.102.053201
published as Phys. Rev. E 102, 053201 (2020) · 12 pages, 9 figures
arxiv created 2020/11/26 · arxiv updated 2020/11/30
We demonstrate through experiments and numerical simulations that low-density, low-loss, meter-scale plasma channels can be generated by employing a conditioning laser pulse to ionize the neutral gas collar surrounding a hydrodynamic optical-field-ionized (HOFI) plasma channel. We use particle-in-cell simulations to show that the leading edge of the conditioning pulse ionizes the neutral gas collar to generate a deep, low-loss plasma channel which guides the bulk of the conditioning pulse itself as well as any subsequently injected pulses. In proof-of-principle experiments we generate conditioned HOFI (CHOFI) waveguides with axial electron densities of ne0 ≈ 1 × 1017 \mathrmcm-3, and a matched spot size of 26 μm. The power attenuation length of these CHOFI channels is Latt = (21 ± 3) m, more than two orders of magnitude longer than achieved by HOFI channels. Hydrodynamic and particle-in-cell simulations demonstrate that meter-scale CHOFI waveguides with attenuation lengths exceeding 1 m could be generated with a total laser pulse energy of only 1.2 J per meter of channel. The properties of CHOFI channels are ideally suited to many applications in high-intensity light-matter interactions, including multi-GeV plasma accelerator stages operating at high pulse repetition rates.