Speaker
Description
All-optical nonlinear Compton scattering (NCS) experiment has been carried out with a multi-PW laser at Center for Relativistic Laser Science (CoReLS). CoReLS finished the construction of a 20 fs, 4 PW Ti:Sapphire laser in 2017 and achieved the record high laser intensity of 10^23 W/cm^2 in 2021. By applying the laser wakefield electron acceleration scheme, mono-energetic multi-GeV electrons were produced by applying PW laser pulses to a He gas medium. In the all-optical NCS demonstration a multi-GeV electron scatters off hundreds of laser photons and converts them into a single gamma-ray photon with energy well over the cutoff energy of linear Compton scattering, i.e. NCS occurs. Along with quantum electrodynamics (QED) simulations and analytic calculations, our experimental measurement of gamma-ray spectra verifies the occurrence of Compton scattering in the strongly nonlinear regime. Our results may help understand the physics associated with QED processes occurring in extreme astrophysical objects such as neutron stars and black holes.
