Spin polarization of electrons by ultraintense lasers

Journal article, 2017

Electrons in plasmas produced by next-generation ultraintense lasers (I > 5 x 10(22)W/cm(2)) can be spin polarized to a high degree (10%-70%) by the laser pulses on a femtosecond time scale. This is due to electrons undergoing spin-flip transitions as they radiate gamma-ray photons, preferentially spin polarizing in one direction. Spin polarization can modify the radiation reaction force on the electrons, which differs by up to 30% for opposite spin polarizations. Consequently, the polarization of the radiated gamma-ray photons is also modified: the relative power radiated in the sigma and pi components increases and decreases by up to 30%, respectively, potentially reducing the rate of pair production in the plasma by up to 30%.