Combined plasma lens and rephasing stage for a laser wakefield accelerator

Cornelia Gustafsson; Erik Löfquist; Kristoffer Svendsen; Andrea Angella; Anders Persson; Olle Lundh

doi:10.1038/s41598-024-78143-6

Combined plasma lens and rephasing stage for a laser wakefield accelerator

Sci Rep. 2024 Nov 1;14(1):26286. doi: 10.1038/s41598-024-78143-6.

Authors

Cornelia Gustafsson¹, Erik Löfquist², Kristoffer Svendsen², Andrea Angella², Anders Persson², Olle Lundh²

Affiliations

¹ Department of Physics, Lund University, P.O. Box 118, Lund, 22100, Sweden. [email protected].
² Department of Physics, Lund University, P.O. Box 118, Lund, 22100, Sweden.

Abstract

Electrons from a laser wakefield accelerator have a limited energy gain due to dephasing and are prone to emittance growth, causing a large divergence. In this paper, we experimentally show that adjusting the plasma density profile can address both issues. Shock-assisted ionisation injection is used to produce 100 MeV quasi-monoenergetic electron bunches in the primary part of the accelerator. Downstream from the accelerator, a second, independently tuneable density region is added, which can be used to either boost the energy of the electron bunches or as a plasma lens for significant divergence reduction. An additional energy gain of 25% and a 40% divergence reduction are obtained. Theoretical models validate the effects.