Fig. 1: Experimental layout.
From: Seeded free-electron laser driven by a compact laser plasma accelerator
The LPA is driven by the DRACO laser (for more details on the DRACO footprint, see ref. 55). The electron beam generated in the LPA is first characterized using a removable electron spectrometer and then sent through a triplet of quadrupoles (QUAPEVAs) for beam transport to the undulator and FEL radiation generation. ICTs, integrated current transformers. Non-labelled elements: dipoles, red blocks; optical lenses, blue disks; mirrors, grey circled black disks. a, Particle-in-cell simulation rendering of the accelerating structure driven by the laser pulse (red); the electron cavity sheet formed from the plasma medium (light blue) is in purple and the accelerated electron bunch in green. b–d, Electron-beam transverse distribution measured at the LPA exit (b), the undulator entrance (c) and the undulator exit (d).
