Fig. 2
From: Seeded X-ray free-electron laser generating radiation with laser statistical properties
Correlation functions and spectra measured in different modes of operation. a–d Intensity correlation functions for seeded (a, c) and self-amplified spontaneous emission (SASE) (b, d) regimes of operation in vertical (a, b) and horizontal (c, d) directions. Spectral structure of an individual pulse (blue line), average spectrum (black line) and Gaussian fit (red dashed line) for seeded (e) and SASE (f) regimes of operation
