Experiments for the laser guiding have been carried out with the 30-fs, 100-TW Ti:sapphier laser pulse interaction with a long slab (1.2*10 (mm)) and discharged capillary of underdense plasma. Formation of an extremely long plasma channel with its length (~10 mm) 10 times above the Rayleigh length is observed when the laser pulse power is much higher than the critical power for relativistic self-focusing. The long self-guiding channel formation is accompanied by the quasi-monoenergetic electron acceleration with a low transverse emittance (<0.8'pi' mm.mrad) and high electric current (up to ~10 nC/shot). In order to continuously elongate the plasma channel, a 4-cm-scale discharged capillary was used. We successfully demonstrated the laser-plasma acceleration of high-quality electron beams up to near GeV. Our results exactly verify the prediction of laser-wakefield acceleration through a centimeter-scale plasma channel in the "blowout bubble" regime, where a micro-scale plasma cavity produced through the ultra-relativistic laser-plasma interactions plays an essential role in the self-injection and acceleration of electrons.
© 2007 Chinese Optics Letters
(190.5530) Nonlinear optics : Pulse propagation and temporal solitons
(270.6620) Quantum optics : Strong-field processes
(290.5910) Scattering : Scattering, stimulated Raman
(350.5400) Other areas of optics : Plasmas
Liming Chen, Kazuhisa Nakajima, Wei Hong, Jianfei Hua, Takashi Kameshima, Hideyuki Kotaki, K. Sugiyama, Xianlun Wen, Yuchi Wu, Chuanming Tang, Yuqiu Gu, Hansheng Peng, Shinichi Kurokawa, James Koga, Sergey V. Bulanov, and Toshiki Tajima, "Elongation of plasma channel for electron acceleration," Chin. Opt. Lett. 5, S133-S135 (2007)