Spin-polarized proton acceleration by an intense laser pulse with a foil-gas target

Abstract

AbstractA novel scheme for obtaining high-energy polarized proton beams by the interaction of a femtosecond laser pulse with a foil-gas composite target has been proposed. The carbon plasmas heated by the laser pulse expand toward the prepolarized HCl gas and excite shock waves in the gas target, reflecting and accelerating spin-polarized protons. According to the results from particle-in-cell simulations with the addition of spin dynamics, protons of several MeV are produced with the polarization rate remaining above 90% in the high energy region. The simulation results show that a large number of the reflected protons are subjected to a weak azimuthal magnetic field and with less depolarization. The intensity of laser pulses and the thickness of foils also affect the strength of the azimuthal magnetic field, which affects the depolarization of the proton beams.