In recent years, laser plasma acceleration (LPA) has become a promising alternative to conventional RF accelerators. Polarized beams are indispensable for many experiments in particle, atomic and nuclear physics as well as in material science, where spin-dependent processes are to be studied. Theoretically, it has been shown that the interaction of multiple laser beams with a gas target can produce polarized electron beams through LPA. The LEAP project at DESY aims to demonstrate this experimentally for the first time.
For this purpose, a LPA for the generation of polarized electron beams will be set up. The electron polarization will be measured with photon transmission polarimetry. It makes use of the production of circularly polarized Bremsstrahlung during the passage of the electrons through a suitable target. The photon polarization is then measured with the aid of the transmission asymmetry related to the magnetization direction of an iron absorber.