Extended Data Fig. 1: Experimental spectra and fits.
From: Testing quantum electrodynamics in extreme fields using helium-like uranium
Projection, with respect to the dispersion axis (x-axis in Fig. 1 proportional to the photon energy), of the spectral lines recorded by the outer spectrometer for the intrashell transition of He-like U (a), Li-like U (b) and Be-like U (c), and the Kα1 line of zinc in second order reflection (d). The best fits to all transitions (solid lines) and the simulation of the He-like transition (dotted line) are also shown. One channel corresponds to 0.079 eV.
