Andreas Döpp among the main authors of a paper published in Nature Communications
The work on ‘Demonstration of relativistic electron beam focusing by a laser-plasma lens’ has been published in Nature Communications. A research team from Laboratoire d’Optique Appliquée (LOA) demonstrates a new laser-plasma lens , providing focusing fields orders of magnitude higher than in conventional beam optics.
Laser-plasma accelerators have the potential to revolutionize accelerator technology as acceleration over just a few millimeters can provide GeV-level electron beams. Applications are hold up by the lack of suitable lens to transport this kind of high-current electron beams mainly due to their divergence. Recently Cédric Thaury from LOA proposed to not only take advantage of the strong longitudinal wakefields, but also to use the transverse fields of the linear wakefield accelerator to reduce the electron beam divergence. Remi Lehe developed a theoretical framework for this kind of laser-plasma lens  and the team led by Professor Victor Malka succeeded shortly after to implement the technology in a proof-of-principle experiment at the Salle Jaune Laser system.
For the study a dual gas jet target was set up. To enable the scanning of the positions between both jets, LA3NET fellow and one of the main authors of the publication, Andreas Döpp designed a new nozzle, which was then produced using 3D printing technology. Together with Emillien Guillaume they performed the experiment, with their supervisors Kim Ta Phuoc and Cédric Thaury.
Depending on the position and density of the second jet they observed a divergence reduction of nearly a factor of three, enough to enable efficient coupling of the laser-accelerated beam to a conventional beam transport line.
A video about his work can be seen here.
 Thaury, C. et al. Demonstration of relativistic electron beam focusing by a laser-plasma lens. Nature Communications 6, 1–5 (2015).
 Lehe, R., et al. Laser-plasma lens for laser-wakefield accelerators. Phys. Rev. Spec. Top.-Accel. Beams 17, 121301 (2014).
C. Thaury, E. Guillaume, A. Döpp, R. Lehe, A. Lifschitz, K. Ta Phuoc, J. Gautier, J-P Goddet, A. Tafzi, A. Flacco, F. Tissandier, S. Sebban, A. Rousse & V. Malka, ‘Demonstration of relativistic electron beam focusing by a laser-plasma lens’, Nature Communications 6: 6860 (2015).