Relatore
Descrizione
The experiment E-320 installed at SLAC FACET-II aims to study QED in the strong field regime.
By colliding 10 GeV, high-quality electron beams with 10 TW NIR laser pulses it is aspired to probe the QED critical (Schwinger) intensity of 10$^{29}$ W$\text{cm}^{-2}$ in the electron rest frame.
In this regime, characterized by $\chi = E^*/E_{\text{cr}} \gtrsim 1$, quantum corrections to classical synchrotron radiation become important and the probability for
electron-positron pair production is no longer exponentially suppressed [1-3].
A central objective of E-320 is to observe the transition from the perturbative ($a_{0}^{2} \ll 1$) to the non-perturbative regime ($a_{0}^{2} \gg 1$), characterized by the intensity parameter $a_{0} = eE/(m c\omega)$, while quantum effects are important (i.e., $\chi{\sim}1$). During this transition, qualitative changes are expected to occur, namely a substantial red-shift of the Compton edges in the photon-emission spectrum and a quasi-continuous spectrum.
We will report on first results from the commissioning run 2022 at $a_{0} < 1$ [4], ongoing developments, and future plans.
[1] A. Fedotov et al., Phys. Rep. (2023)
[2] A. Gonoskov et al., Rev. Mod. Phys. (2022)
[3] A. Di Piazza et al., Rev. Mod. Phys. (2012)
[4] C. Clarke et al., LINAC2022 (2022)
