Title :
Channel guiding for laser wakefield accelerators
Author :
Leemans, W.P. ; Volfbeyn, P. ; Archambault, L. ; Catravas, P. ; DiMaggio, S. ; Esarey, E.
Author_Institution :
Lawrence Berkeley Nat. Lab., California Univ., Berkeley, CA, USA
Abstract :
Experimental investigations of laser guiding in plasma channels at LBNL are reported. Intense (>2×1017 W/cm2), short (60 fs) laser pulses have been injected and guided in slab or cylindrical channels. The channels are produced in H 2 gas, delivered by a high pressure gas jet, with the dual-pulse Ignitor-Heater technique. Using cylindrical focusing optics, a first ultrashort (<100 fs) laser pulse (Ignitor), is brought to a line focus to ionize the gas jet. A second 160 ps long laser pulse (Heater) is subsequently used to heat the existing spark via inverse bremsstrahlung. The hydrodynamic shock expansion creates a channel. The channel profile is diagnosed with time resolved longitudinal interferometry. The effects of laser beam size and divergence mismatch at the channel entrance and leakage of the laser energy out of the channel are studied in 1D and 2D
Keywords :
bremsstrahlung; optical focusing; plasma light propagation; wakefield accelerators; 100 fs; 160 fs; 60 fs; H2; channel guiding; cylindrical focusing optics; dual-pulse Ignitor-Heater technique; gas jet; hydrodynamic shock expansion; inverse bremsstrahlung; laser beam divergence mismatch; laser beam size; laser energy loss; laser guiding; laser pulse; laser wakefield accelerators; plasma channels; time resolved longitudinal interferometry; Acceleration; Electric shock; Energy resolution; Gas lasers; Hydrodynamics; Optical interferometry; Optical pulses; Plasma accelerators; Slabs; Sparks;
Conference_Titel :
Particle Accelerator Conference, 1999. Proceedings of the 1999
Conference_Location :
New York, NY
Print_ISBN :
0-7803-5573-3
DOI :
10.1109/PAC.1999.795696
