Figure 2.

Performance of the MuCLS operated at the 35 keV X-ray configuration. The inset depicts the maximum X-ray flux of 5 × 10¹⁰ photons s⁻¹ achieved under optimal conditions. However, this flux has been reached only briefly during X-ray optimization so far. Typically, small movements of the electron beam within the stability range of the storage ring in conjunction with adjustments of the temporal delay between laser and electron beam are sufficient for daily X-ray tuning. On timescales required for experiments, this X-ray flux stabilizes at a level of 4.0 × 10¹⁰ to 4.3 × 10¹⁰ photons s⁻¹ under such circumstances, as shown in the main figure. Data were recorded with the beam-monitoring system described by Günther et al. (2019 ▸).