@article {0741-3335-58-3-034011,
	title = {Laser wakefield and direct acceleration with ionization injection},
	journal = {Plasma Physics and Controlled Fusion},
	volume = {58},
	year = {2016},
	pages = {034011},
	abstract = {We demonstrate using particle-in-cell simulations that electrons can be injected into a hybrid laser wakefield and direct laser accelerator via ionization injection. We propose an accelerator and injector scenario that utilizes two laser pulses. The first (pump) pulse produces the plasma {\textquoteleft}bubble{\textquoteright} by expelling the plasma electrons generated by its leading edge from the low-Z component of the gas mixture, and then injects electrons into the bubble by ionizing the high-Z component. The second time-delayed laser pulse resonantly interacts with these injected electrons undergoing betatron oscillations inside the bubble. We show that the electrons ionized off-axis and on-axis but off the peak ionization phase possess sufficient transverse energy to undergo efficient direct laser acceleration (DLA). When combined with their acceleration by the bubble{\textquoteright}s longitudinal plasma wake, DLA can double the total energy gain and produce a monoenergetic beam.},
	url = {http://stacks.iop.org/0741-3335/58/i=3/a=034011},
	author = {Xi Zhang and Vladimir N. Khudik and Alexander Pukhov and Gennady Shvets}
}
