RELATIVISTIC ELECTRON DYNAMICS IN PETAWATT LASER FIELDS WITH APPLICATIONS TO FUNDAMENTAL MEASUREMENTS

Abstract

Multi-petawatt lasers provide unprecedented access to test nearly century-old predictions of nonlinear quantum electrodynamics (QED). Realizing laser-based precision measurements of nonlinear QED effects, however, requires overcoming various critical challenges, including (i) reliably characterizing the focal volume in real time at full power and (ii) minimizing the presence of real particles in the focal volume that can have adverse effects.This dissertation demonstrates that both challenges can be addressed by exploiting the dynamics of electrons liberated from residual gas in the focal volume and subsequently expelled at acute angles relative to the direction of laser propagation. Through a series of experiments and numerical simulations, it is shown that the spatial distribution of these ejected electrons provides critical information about the peak intensity, aberrations, and the presence of deleterious particles in the focal volume. These results establish a practical pathway toward state-of-the-art measurements of nonlinear QED effects in the near future.