Sep 15 – 21, 2019
Hotel Hermitage, La Biodola Bay, Isola d'Elba, Italy
Europe/Rome timezone

Simulations of a wakefield dissipation in a radially bounded plasma

Sep 16, 2019, 7:00 PM
Parking Area (Hotel Hermitage)

Parking Area

Hotel Hermitage

poster WG6 - Theory and simulations Cheese and Wine Poster Session 1


Konstantin Lotov (Novosibirsk State University)


In modern experiments on plasma wakefield acceleration, relativistic electron bunches (or laser pulses) excite plasma wakes with energy density comparable to the rest energy density of plasma electrons. Breaking of such wake in a radially bounded plasma is followed by its energy redistribution between hot electrons, electric fields and radial ion motion and leads to plasma column expansion via ionization of surrounding gas. This relaxation dynamics determines repetition rate of plasma accelerators. Recent E224 experiments at the SLAC FACET provided ps-time-resolved optical shadowgraphic measurements of plasma density profiles after the passage of drive electron bunch. Results demonstrate growth of the plasma column radius with a nearly constant velocity from ~100 μm to ~2 mm over 1.5 ns.
This work presents results of numerical simulations of long-term plasma column evolution in this experiment. It is shown that a fraction of electrons expelled by the bunch from plasma column propels radial ion motion. Ions at the front of expansion wave create seed plasma through ion-impact ionization. Appearance of slow electrons at given location leads to subsequent exponential plasma density growth due to electron-impact multistage ionization. Quantitative agreement with the experimental data is achieved via simultaneous consideration of all the described microscopic effects.

Primary authors

Vadim Khudyakov Konstantin Lotov (Novosibirsk State University) Alexander Sosedkin (Novosibirsk State University)


Rafal Zgadzaj (University of Texas at Austin) Michael Downer (The University of Texas at Austin) Thales Silva (GoLP/Instituto Superior Técnico (Lisbon)) Jorge Vieira (Instituto Superior Tecnico) Spencer Gessner (CERN) Mark Hogan (SLAC National Accelerator Laboratory) Michael Litos (University of Colorado Boulder) Vitaly Yakimenko (SLAC)

Presentation materials