Next-generation Plasma-based Electron Beam Sources for High-brightness Photon Science

Project Information

NeXource

Grant agreement ID: 865877

DOI

10.3030/865877

EC signature date 7 February 2020

Start date 1 April 2020

End date 30 September 2026

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 2 059 493,00

EU contribution

€ 2 059 493,00

Coordinated by

HEINRICH-HEINE-UNIVERSITAET DUESSELDORF
Germany

Periodic Reporting for period 4 - NeXource (Next-generation Plasma-based Electron Beam Sources for High-brightness Photon Science)

Reporting period: 2024-09-01 to 2025-09-30

Summary of the context and overall objectives of the project

Particle accelerators have many uses in fundamental and applied science, but conventional particle accelerators are huge. Plasma wakefield accelerators exploit plasma, a state of matter where electrons and ions are separated from each other, and can generate electric accelerating fields 1000 times stronger than in conventional accelerators. In turn, they can be used to shrink the size of particle accelerators by the same factor. However, the output beam quality from plasma accelerators is not better, and often worse than from conventional sources. The project addresses this crucial point and follows the approach of the plasma photocathode, that promises electron beams of much better quality than from conventional accelerators to be produced. In particular, the electron beams from plasma photocathodes may be up to 100,000 times brighter than state-of-the-art. Such Next Generation Plasma-based Electron Beam Sources (NeXource) would have large impact e.g. for intense photon sources such as X-ray free-electron-lasers. Such X-ray lasers are enormously important e.g. for material and biophysics, because they enable imaging of ultrafast atomic processes, e.g. the motion of electrons inside atoms and molecules.
The overarching objective of NeXource is to produce 1000x smaller and at the same time 100,000x brighter electron beams, thereby opening up completely new capabilities and at the same time democratizing particle accelerators by making them smaller, cheaper and simpler.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In order to realize the ambitious objectives, a double envelopment is applied. On the one hand, stable electron beams from conventional accelerators are used as drivers for the plasma wave, and on the other hand, electron beams from compact laser-plasma-accelerators are used. Both approaches have largely complementary features and challenges, and by exploiting both avenues the desired breakthrough may be achieved.
One success highlight is the experimental demonstration of a new class of plasma accelerators, so called hybrid-laser-plasma wakefield accelerators. Here, electron beams from a compact laser-plasma-accelerator are then used to drive the plasma wave with the desired characteristics. A popular summary can be found here: https://www.strath.ac.uk/whystrathclyde/news/2021/anewtypeofminiatureplasmaparticleaccelerator/ This “hybrid” plasma wakefield accelerator platform was then used to realize several electron beam injection methods, and milestone towards the realization of plasma photocathodes with such systems was obtained recently, a summary can be found here: https://physics.aps.org/articles/v15/s160
This rapid progress in the hybrid plasma wakefield accelerator arena is driven forward as a European collaboration of researchers from the UK, Germany and France, and is also an important element in the EuPRAXIA project, which is now on the ESFRI roadmap of large European infrastructures.
Meanwhile, progress ramps up at Stanford in the SLAC FACET-II facility, where the electron beam will be used to realize advanced versions of plasma photocathodes in the E-310: Trojan Horse-II collaboration.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The project work package on hybrid plasma wakefield accelerators has progressed faster than anticipated. Partially this can be attributed to somewhat reduced impacts of the pandemic on operation of these machines, whereas progress at conventional accelerators is more prone to pandemic-related delays – an advantage of compact laser-plasma-accelerator setups unforeseen before the start of the project.
In the future, advanced experiments are in preparation that will demonstrate the full potential of plasma photocathodes with both types of accelerators.
At the same time, in a related effort the NeXource PI and their team is working on the design of novel X-ray lasers, anticipating the further success of plasma photocathodes and ultrabright electron beam production, and planning their exploitation.

OutlookSchwingerQED.PNG