sentences:  When the amplification process is complete the laser light enters the experimental chamber, lying at one end of the building.Here it is reflected off a series of deformable mirrors that help correct remaining imperfections in the wavefront, and then feeds them into the target chamber from all angles.Since the overall distances from the ends of the beamlines to different points on the target chamber are different, delays are introduced on the individual paths to ensure they all reach the center of the chamber at the same time, within about 10 picoseconds (ps).