Extended Data Fig. 4: Simulation of a seeded FEL at 40 nm.
From: Seeded free-electron laser driven by a compact laser plasma accelerator
Simulation of a seeded FEL at 40 nm. a,b. Electron beam energy and peak current (a), and energy spread (b) as a function of the spatial extent of the stretched bunch. In (c) is depicted the peak power along the undulator, with the GW level sketched by a red dashed line. Inset in (c) presents the FEL spectrum at the undulator exit. Beam parameters at source point: energy of 400 MeV, bunch length of 2 μm–rms, emittance of (0.3, 0.2) mm.mrad, divergence of (1.2, 0.8) mrad-rms, charge of 1450 pC. Chicane strength: R56 = -1 mm. Undulator parameters: period 15 mm, number of periods = 200. Seed parameters: pulse energy of 5 nJ, Rayleigh length of 15 m, waist at 5 m upstream undulator.
