Ultrafast polarization of an electron beam in an intense bichromatic laser field

• Published in: Physical review. A 2019-12, Vol.100 (6), Article 061402
• Main Authors: Seipt, Daniel, Del Sorbo, Dario, Ridgers, Christopher P., Thomas, Alec G. R.
• Format: Article
• Language: English
• Subjects: beam polarization; high intensity laser-plasma interactions; Monte Carlo methods; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; polarization; radiation & particle generation in plasmas; spin
• ISSN: 2469-9926; 2469-9934
• DOI: 10.1103/PhysRevA.100.061402

In this work, we demonstrate the radiative polarization of high-energy electron beams in collisions with ultrashort pulsed bichromatic laser fields. Employing a Boltzmann kinetic approach for the electron distribution allows us to simulate the beam polarization over a wide range of parameters and determine the optimum conditions for maximum radiative polarization. Those results are contrasted with a Monte Carlo algorithm where photon emission and associated spin effects are treated fully quantum mechanically using spin-dependent photon emission rates. The latter method includes realistic focusing laser fields, which allows us to simulate a near-term experimentally feasible scenario of an 8 GeV electron beam scattering from a 1 PW laser pulse and provide a measurement that would verify the ultrafast radiative polarization in high-intensity laser pulses that we predict. Aspects of spin-dependent radiation reaction are also discussed, with spin polarization leading to a measurable (5%) splitting of the energies of spin-up and spin-down electrons.