Acceleration of spin-polarized proton beams via two parallel laser pulses
We present a setup for highly polarized proton beams using two parallel propagating laser pulses that have a carrier envelope phase difference of $\pi$. This mechanism is examined utilizing particle-in-cell simulations and compared to a single-pulse setup commonly used for magnetic vortex acceleration. We find that the use of the dual-pulse setup allows for peak energies of 124 MeV and good angular spread for two pulses with normalized laser vector potential $a_0 = 100$. Compared to a single pulse, we further observe higher polarization of the accelerated bunch.