You are probably familiar with CERN, and the Large Hadron Collider (LHC), the largest science experiment in the world. A huge particle accelerator where protons are smashed into each other to produce other exotic particles in order to learn more about our cosmos. Now imagine, something smaller and just as powerful. That is the dream a laboratory in sunny California is trying to achieve.
At the Department of Energy’s SLAC National Accelerator Laboratory, a different kind of particle accelerator exists: FACET-II. This particle accelerator uses the same material that the sun is made of, a plasma, as the medium in which particles are accelerated. Plasma is the fourth state of matter and can be thought of as a really hot gas. So hot in fact that atoms no longer exist, and the electrons are stripped from their atoms and a ‘soup’ of ions and electrons are left behind. In essence, plasma accelerators work by producing plasma waves with an electron beam and causing electrons to ride the plasma waves just like surfing. The following video made by SLAC explains exactly how the plasma accelerator, FACET works.
In early 2020, the FACET-II facility aims to open for use by scientists across the world. Plasma accelerators are compact accelerators that are more affordable . FACET-II will be the upgraded version of the current FACET facility. Where the aim of the upgrade is to get the electron beam brighter by about 100 or even 1000 times. FACET-II will be the home of experiments that will add to medical and x-ray science, and particle physics. Currently, potential users are submitting proposals for experiments they would like to carry out at FACET-II. A program advisory committee will evaluate the proposals and select the most exciting ones with the largest impact in science for the upcoming experimental runs.
Most of the proposals submitted have focussed on improving and tackling current problems with plasma accelerators so that they can be made smaller and higher energy. The long-term aim is to be able to build plasma accelerators that can offer the same energies are large, more conventional accelerators at a fraction of the size. Some experiments hope to improve the preservation of the electron beam quality and increase the brightness. Other experiments would like to investigate different electron beams for making powerful x-ray lasers.
Of course, there is some exciting science in the field of plasma accelerators on the way, so watch this space.