Fig. 2: Spectral analysis under different operation modes.
From: Terawatt-attosecond hard X-ray free-electron laser at high repetition rate
a–i, Spectral measurements and corresponding histograms for the number of spikes under the regular operation (a–c), after self-chirping (d–f) and arc compression (g–i) at a 10 Hz repetition rate. The left panels show 100 consecutive single-shot spectral measurements, the centre panels show a typical single-shot spectrum, and the right panels depict histograms based on 800 consecutive spectra.
