Comment on “Creation of Electron-Positron Pairs in Photon-Photon Collisions Driven by 10-PW Laser Pulses”

Figure 1

(a)–(c) Density of electrons and ions in 2D PIC simulations at 200 fs; (d) and (e) spectral-angular distributions of $\gamma$ rays by 700 fs for immobile and mobile cases, where ${\theta }_{\gamma }=\mathrm{atan}(p_y/p_x)$ and $s_{\gamma }={\log }_{10}({\epsilon }_{\gamma }/\mathrm{MeV})$; (f) pairs generated by photons from (d) and (e) with the divergence angle less than $|{\theta }_{\gamma }|$.