TY - JOUR
T1 - The role of the gas/plasma plume and self-focusing in a gas-filled capillary discharge waveguide for high-power laser-plasma applications
AU - Ciocarlan, Cristian
AU - Wiggins, Mark
AU - Islam, Mohammad
AU - Ersfeld, Bernhard
AU - Abu-Azoum, Salima Saleh
AU - Wilson, Robbie
AU - Aniculaesei, Constantin
AU - Welsh, Gregor H.
AU - Vieux, Gregory
AU - Jaroszynski, Dino
PY - 2013
Y1 - 2013
N2 - The role of the gas/plasma plume at the entrance of a gas-filled capillary discharge plasma waveguide in increasing the laser intensity has been investigated. Distinction is made between neutral gas and hot plasma plumes that, respectively, develop before and after discharge breakdown. Time-averaged measurements show that the on-axis plasma density of a fully expanded plasma plume over this region is similar to that inside the waveguide. Above the critical power, relativistic and ponderomotive self-focusing lead to an increase in the intensity, which can be nearly a factor of 2 compared with the case without a plume. When used as a laser plasma wakefield accelerator, the enhancement of intensity can lead to prompt electron injection very close to the entrance of the waveguide. Self-focusing occurs within two Rayleigh lengths of the waveguide entrance plane in the region, where the laser beam is converging. Analytical theory and numerical simulations show that, for a density of 3.0 × 1018 cm−3, the peak normalized laser vector potential, a 0, increases from 1.0 to 1.85 close to the entrance plane of the capillary compared with a 0 = 1.41 when the plume is neglected.
AB - The role of the gas/plasma plume at the entrance of a gas-filled capillary discharge plasma waveguide in increasing the laser intensity has been investigated. Distinction is made between neutral gas and hot plasma plumes that, respectively, develop before and after discharge breakdown. Time-averaged measurements show that the on-axis plasma density of a fully expanded plasma plume over this region is similar to that inside the waveguide. Above the critical power, relativistic and ponderomotive self-focusing lead to an increase in the intensity, which can be nearly a factor of 2 compared with the case without a plume. When used as a laser plasma wakefield accelerator, the enhancement of intensity can lead to prompt electron injection very close to the entrance of the waveguide. Self-focusing occurs within two Rayleigh lengths of the waveguide entrance plane in the region, where the laser beam is converging. Analytical theory and numerical simulations show that, for a density of 3.0 × 1018 cm−3, the peak normalized laser vector potential, a 0, increases from 1.0 to 1.85 close to the entrance plane of the capillary compared with a 0 = 1.41 when the plume is neglected.
KW - gas/plasma plume
KW - neutral gas
KW - hot plasma plumes
KW - plasma density
KW - laser plasma wakefield accelerator
UR - http://www.scopus.com/inward/record.url?scp=84885053701&partnerID=8YFLogxK
UR - http://scitation.aip.org/content/aip/journal/pop
U2 - 10.1063/1.4822333
DO - 10.1063/1.4822333
M3 - Article
SN - 1070-664X
VL - 20
JO - Physics of Plasmas
JF - Physics of Plasmas
M1 - 093108
ER -