Generation of ultrabrilliant polarized attosecond electron bunch via dual-wake injection

TL;DR

This paper proposes a dual-wake injection scheme using a radially polarized laser to generate ultrashort, highly polarized, and bright triplet electron bunches with potential applications in ultrafast imaging and high-energy physics.

Contribution

It introduces a novel dual-wake injection method in laser wakefield acceleration to produce ultrashort, polarized electron bunches with high brightness, demonstrated through 3D particle-in-cell simulations.

Findings

Electron bunch duration about 500 attoseconds

Six-dimensional brightness exceeds 10^14 A/m^2/0.1%

Polarization over 80% achieved

Abstract

Laser wakefield acceleration is paving the way for the next generation of electron accelerators, for their own sake and as radiation sources. A controllable dual-wake injection scheme is put forward here to generate an ultrashort triplet electron bunch with high brightness and high polarization, employing a radially polarized laser as a driver. We find that the dual wakes can be driven by both transverse and longitudinal components of the laser field in the quasi-blowout regime, sustaining the laser-modulated wakefield which facilitates the sub-cycle and transversely-split injection of the triplet bunch. {Polarization of the triplet bunch can be highly preserved due to the laser-assisted collective spin precession and the non-canceled transverse spins. In our three-dimensional particle-in-cell simulations, the triplet electron bunch, with duration about $500$ as, six-dimensional brightness exceeding $10^{14}$ A/m$^2$/0.1$\%$ and polarization over $80\%$, can be generated using a few-terawatt laser}. Such an electron bunch could play an essential role in many applications, such as ultrafast imaging, nuclear structure and high-energy physics studies, and the operation of coherent radiation sources.