Fig. 3: 2D spectra and divergence of high-order harmonics (HHs) in different gas medium.
From: High efficiency ultrafast water-window harmonic generation for single-shot soft X-ray spectroscopy
Experimental spectra showing both the photon energy (horizontal axis) and divergence (vertical axis) in different gases: (a, b) Ar, (c, d) Ne, and (e, f) He. (b), (d), and (f) present the beam divergence profiles for 60–80 eV in (a), 240–260 eV in (c), and 290–310 eV in (e), respectively.
