Extended Data Fig. 3: Simulation results obtained by increasing the beam charge.

a, The simulated angle-resolved energy-dispersed beam distributions obtained by increasing the beam charge Q from 20 fC to 1 pC and 2pC, while keeping other parameters invariant, with zf = −3.5 mm and np = 6 × 1017 cm−3. b, The corresponding energy spectra. c, The corresponding evolutions of the normalized beam emittance.