The laser-induced plasma wakefield in a capillary is investigated on the basis of a simple two-dimensional analytical model. It is shown that as an intense laser pulse reshaped by the capillary wall propagates in capi...The laser-induced plasma wakefield in a capillary is investigated on the basis of a simple two-dimensional analytical model. It is shown that as an intense laser pulse reshaped by the capillary wall propagates in capillary plasma, it resonantly excites a strong wakefield if a suitable laser pulse width and capillary radius are chosen for a certain plasma density. The dependence of the laser width and capillary radius on the plasma density for resonance conditions is considered. The wakefield amplitude and longitudinal scale of bubbles in capillary plasma are much larger than those in unbounded plasma, so the capillary guided plasma wakefield is more favorable to electron acceleration.展开更多
We measured the parameter reproducibility and radial electron density profile of capillary discharge waveguides with diameters of 650µm to 2 mm and lengths of 9 to 40 cm.To the best of the authors’knowledge,40 c...We measured the parameter reproducibility and radial electron density profile of capillary discharge waveguides with diameters of 650µm to 2 mm and lengths of 9 to 40 cm.To the best of the authors’knowledge,40 cm is the longest discharge capillary plasma waveguide to date.This length is important for≥10 GeV electron energy gain in a single laser-driven plasma wakefield acceleration stage.Evaluation of waveguide parameter variations showed that their focusing strength was stable and reproducible to<0.2%and their average on-axis plasma electron density to<1%.These variations explain only a small fraction of laser-driven plasma wakefield acceleration electron bunch variations observed in experiments to date.Measurements of laser pulse centroid oscillations revealed that the radial channel profile rises faster than parabolic and is in excellent agreement with magnetohydrodynamic simulation results.We show that the effects of non-parabolic contributions on Gaussian pulse propagation were negligible when the pulse was approximately matched to the channel.However,they affected pulse propagation for a non-matched configuration in which the waveguide was used as a plasma telescope to change the focused laser pulse spot size.展开更多
基金supported by National Natural Science Foundation of China (No.11047152)the Natural Science Foundation of Jiangxi Province of China (No.2010GQW0048)
文摘The laser-induced plasma wakefield in a capillary is investigated on the basis of a simple two-dimensional analytical model. It is shown that as an intense laser pulse reshaped by the capillary wall propagates in capillary plasma, it resonantly excites a strong wakefield if a suitable laser pulse width and capillary radius are chosen for a certain plasma density. The dependence of the laser width and capillary radius on the plasma density for resonance conditions is considered. The wakefield amplitude and longitudinal scale of bubbles in capillary plasma are much larger than those in unbounded plasma, so the capillary guided plasma wakefield is more favorable to electron acceleration.
基金the Director,Office of Science,Office of High Energy Physics,of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231used the computational facilities at the National Energy Research Scientific Computing Center(NERSC)as well as the project High Field Initiative(No.CZ.02.1.01/0.0/0.0/15_003/0000449)from the European Regional Development Fund.
文摘We measured the parameter reproducibility and radial electron density profile of capillary discharge waveguides with diameters of 650µm to 2 mm and lengths of 9 to 40 cm.To the best of the authors’knowledge,40 cm is the longest discharge capillary plasma waveguide to date.This length is important for≥10 GeV electron energy gain in a single laser-driven plasma wakefield acceleration stage.Evaluation of waveguide parameter variations showed that their focusing strength was stable and reproducible to<0.2%and their average on-axis plasma electron density to<1%.These variations explain only a small fraction of laser-driven plasma wakefield acceleration electron bunch variations observed in experiments to date.Measurements of laser pulse centroid oscillations revealed that the radial channel profile rises faster than parabolic and is in excellent agreement with magnetohydrodynamic simulation results.We show that the effects of non-parabolic contributions on Gaussian pulse propagation were negligible when the pulse was approximately matched to the channel.However,they affected pulse propagation for a non-matched configuration in which the waveguide was used as a plasma telescope to change the focused laser pulse spot size.
