The Plasma Injector for PETRA IV: Enabling Plasma Accelerators for Next-generation Light Sources. Conceptual Design Report

We present the conceptual design of an alternative injector system based on laser-plasma accelerator technology, to deliver high-quality electron bunches to PETRA IV – the future 4th generation synchrotron light source at DESY. The design consists of a laser-plasma accelerator to produce electron bunches at 6 GeV with state-of-the-art energy spread and stability (∼1%), and an X-band energy compressor beamline to further reduce the overall beam energy deviations down to a sub-permille level, thus maximizing the charge injection throughput into the PETRA IV storage ring. Driven by the Petawatt upgrade of DESY’s new flagship laser KALDERA, the plasma injector system can be used to top up the PETRA IV storage ring, significantly lowering the load on the RF injector chain. Ultimately, upon further development of high-efficiency, high-power laser drivers that operate at high repetition rates, the plasma injector could replace the RF-based system in the future to reduce the spatial footprint and energetic cost of the whole injector complex.