The particle accelerator in question is a plasma wakefield accelerator, which generates short and intense bursts of electrons, and the laser it's powering is what's known as a free-electron laser (FEL), which uses its light to analyze atoms, molecules, and condensed matter in incredibly high resolutions.

The emitted light pushes back on the electrons, pushing them into smaller groups that then generates the laser beam.

Not only is the new setup smaller than your standard particle accelerator and FEL configuration, it's also much more affordable as well – which opens up all kinds of potential new applications, even if the device isn't as powerful as the full-scale versions.