Abstract
The SPring-8 Ångstrom Compact free-electron LAser (SACLA) began parallel operation of three beamlines (BL1-3) in autumn 2017 to increase the user beam time of the X-ray free-electron laser. The success of the multiple-beamline operation is based on two technological achievements: (i) the fast switching operation of the SACLA main linear accelerator, which provides BL2 and BL3 with pulse-by-pulse electron beams, and (ii) the relocation and upgrade of the SPring-8 Compact SASE Source for BL1, for the generation of a soft X-ray free-electron laser. Moreover, the photon beamlines and experimental stations were upgraded to facilitate concurrent user experiments at the three beamlines and accommodate more advanced experiments.