7th International Conference on Matter and Radiation at Extremes (ICMRE2024)

While the acceleration of spin-polarized ions from laser-plasma interactions has recently been experimentally verified [1], it has become clear that maintaining a high degree of polarization strongly depends on presence of inhomogeneous electromagnetic fields during the acceleration process. Thus, applications with high laser intensity require elaborate acceleration schemes to prevent significant depolarization.

In this talk, we present an acceleration scheme for spin-polarized ³He in the regime of a₀ = 100-200. Our setup utilizes a solid Carbon foil in front of the near-critical Helium target. The laser pulse heats up the Carbon foil, inducing subsequent Collisionless Shock Acceleration of the Helium ions [2].

Our particle-in-cell simulations show that polarization on the 90%-level and energies in the range of hundreds of MeV are achievable using this mechanism. This is a strong improvement over the lower polarization obtained in Magnetic Vortex Acceleration, even at lower laser intensities [3]. We further are able to show that the radiation reaction force leads to increased beam charge due to an improved matching of the trapping condition for the shock wave.