Shock-front injector for high-quality laser-plasma acceleration
A. Buck, J. Wenz, J. Xu, K. Khrennikov, K. Schmid, M. Heigoldt, J. M. Mikhailova, M. Geissler, B. Shen, F. Krausz, S. Karsch, and L. Veisz
Accepted
We report the generation of stable and tunable electron bunches with very low absolute energy spread (DE 5 \textMeV) accelerated in laser wakefields via injection and trapping at a sharp downward density jump produced by a shock front in a supersonic gas flow. The peak of the highly stable and reproducible electron energy spectrum was tuned over more than one order of magnitude, containing a charge of 1-100 pC and a charge per energy interval of more than 10 pC/MeV. Laser-plasma electron acceleration with Ti:Sapphire lasers using this novel injection mechanism provides high quality electron bunches tailored for applications.