Positron collimation driven by channel fields excited by a Doppler-boosted laser pulse in the prefilled target

We propose an all-optical configuration for the integrated generation, collimation, and acceleration of positrons with laser–electron beam interaction in a channel target. The electromagnetic fields driven by a Doppler-boosted laser within the channel yield a high-collimated dense positron bunch (with a peak density of ∼1028 m−3 and a duration of ∼27 fs). With the channel target, the beam divergence angle (FWHM) is decreased from 40° to 23°, and the monoenergetic peak is expected to upshift to hundreds of MeV. Moreover, automatic spatial and spectral separation between positrons and background electrons is also achieved, providing a promising scheme for future high-quality positron generation in compact integrated devices.