LUX was the first laser-plasma accelerator to combine modern (conventional) accelerator technology with plasma acceleration concepts, introducing a paradigm shift towards highly controllable and stable machines.

With LUX we demonstrated the first-ever day-long operation of a laser-plasma accelerator, developed novel plasma sources for high-quality electron beams, and pioneered machine learning-based optimization methods.

Currently, LUX serves as a testbed for the development of a laser-plasma based injector for synchrotron light sources.

What sets LUX apart from most other laser-plasma accelerators is its advanced electron beamline, a direct result of DESY’s world-renowned expertise in accelerator technology. The LUX beamline offers unparalleled capabilities in beam manipulation and precision diagnostics. This sophisticated setup is crucial for our investigations into laser-plasma-based light sources and the development of innovative beam dynamics schemes tailored for compact synchrotron injectors. Moreover, the beamline’s versatility accommodates a broad range of experimental needs.

LUX is powered by the ANGUS laser system, a titanium-sapphire laser delivering pulses up to 5-joule pulse energy at around 30 femtoseconds pulse length. Consistent with our rigorous approach at LUX, ANGUS is meticulously monitored across all parameters, ensuring precise control and stability. We have implemented several drift compensation systems, maintaining stable operating conditions over extended periods, including day-long operations. ANGUS's reliability and precision are key to the sustained performance of LUX.

At the core of every laser-plasma accelerator is the plasma source. To achieve optimal beam quality, it is crucial to fully understand and control the dynamics within the plasma to identify the optimum setpoint for the many tuning parameters of the machine. We pioneered the approach of introducing advanced machine learning methods to control and optimize the properties of the laser and the accelerated electrons. By leveraging these techniques, we can efficiently navigate the vast parameter space, automatically adjusting settings to maintain peak performance and consistency in beam quality.

The complete beamline, including the laser-plasma interaction and the electron beam dynamics is model with start-to-end simulations. We use FBPIC to rapidly run simulations that replicate experimental conditions or explore new and exciting regimes for future experiments. Additionally, we have a custom beam dynamics code that precisely models real-world aspects of our beamline, such as field errors in the magnets and the effects of the Earth's magnetic field. The code enables fast online optimization of the beam optics.

Compact X-ray sources are among the most promising applications of laser-plasma accelerators. At LUX, we have demonstrated the 24-hour-long generation of water window X-rays using the BEAST II undulator. Currently, we are studying plasma-driven undulator radiation from the FROSTY variable-gap cryogenic undulator, that we have developed together with the group of J. Bahrdt (Helmholtz Center Berlin).