Demonstration of a narrow energy spread, ∼0.5GeV electron beam from a two-stage laser wakefield accelerator
Pollock BB., Clayton CE., Ralph JE., Albert F., Davidson A., Divol L., Filip C., Glenzer SH., Herpoldt K., Lu W., Marsh KA., Meinecke J., Mori WB., Pak A., Rensink TC., Ross JS., Shaw J., Tynan GR., Joshi C., Froula DH.
Laser wakefield acceleration of electrons holds great promise for producing ultracompact stages of GeV scale, high-quality electron beams for applications such as x-ray free electron lasers and high-energy colliders. Ultrahigh intensity laser pulses can be self-guided by relativistic plasma waves (the wake) over tens of vacuum diffraction lengths, to give >1GeV energy in centimeter-scale low density plasmas using ionization-induced injection to inject charge into the wake even at low densities. By restricting electron injection to a distinct short region, the injector stage, energetic electron beams (of the order of 100MeV) with a relatively large energy spread are generated. Some of these electrons are then further accelerated by a second, longer accelerator stage, which increases their energy to ∼0.5GeV while reducing the relative energy spread to <5% FWHM. © 2011 American Physical Society.