Autor: |
Yu LL; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA and Department of Physics, University of California, Berkeley, California 94720, USA and Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China., Esarey E; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Schroeder CB; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Vay JL; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Benedetti C; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Geddes CG; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA., Chen M; Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China., Leemans WP; Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA and Department of Physics, University of California, Berkeley, California 94720, USA. |
Abstrakt: |
A method is proposed to generate femtosecond, ultralow emittance (∼10-8 m rad), electron beams in a laser-plasma accelerator using two lasers of different colors. A long-wavelength pump pulse, with a large ponderomotive force and small peak electric field, excites a wake without fully ionizing a high-Z gas. A short-wavelength injection pulse, with a small ponderomotive force and large peak electric field, copropagating and delayed with respect to the pump laser, ionizes a fraction of the remaining bound electrons at a trapping wake phase, generating an electron beam that is accelerated in the wake. |