Towards experimental measurements of strong-field QED effects with high-intensity lasers

Strong-field quantum electrodynamics (QED) processes are predicted to play a dominant role in the interaction of next-generation high-intensity (> 10^23W/cm^2) laser pulses with matter. In particular quantum radiation reaction will play a major role in the motion of the electrons and positrons in the plasma created in the laser focus. Until recently quantum radiation reaction had not been studied in the relevant regime in the laboratory.  First measurements of radiation reaction in the collision of a high-intensity (>10^20W/cm^2) laser-pulse with a laser wakefield accelerated electron beam will be discussed which hint at the importance of quantum corrections.  Recent work will be presented further elucidating the signatures of quantum radiation reaction in this all optical collider set-up and pointing the way to a definitive test of the quantum model of radiation reaction in future experiments. In particular we will show a new theoretical (quantum kinetic) framework in which the degree of broadening of the energy spectrum of the beam due to quantum stochasticity may be quantified. We will then discuss signatures of quantum radiation reaction in laser-plasma interactions as intensities surpass 10^22W/cm^2. Radiation reaction can lead to strong absorption of the laser pulse and quantum corrections strongly affect this. We will compare radiation-reaction mediated laser absorption in PIC simulations using quantum and classical frameworks for the first time, demonstrating the importance of quantum radiation reaction effects in this type of interaction.