2024/02/21 by Yipeng Wu, Wu, Yipeng, Audrey Farrell +27
Engineering · Physics and Astronomy · #FOS: Physical sciences #Ionosphere and magnetosphere dynamics #Laser-induced spectroscopy and plasma #Plasma Physics (physics.plasm-ph) #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2402.13493
openalex publication_date 2024/02/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
When a moderately intense, few-picoseconds long laser pulse ionizes gas to produce an underdense plasma column, a linear relativistic plasma wave or wake can be excited by the self-modulation instability that may prove useful for multi-bunch acceleration of externally injected electrons or positrons to high energies in a short distance. At the same time, due to the anisotropic temperature distributions of the ionized plasma electrons, the Weibel instability can self-generate magnetic fields throughout such a plasma on a few picosecond timescale. In the present paper we first show using simulations that both these effects do indeed co-exist in space and time in the plasma. Using our simulations, we make preliminary estimates of the transverse emittance growth of an externally injected beam due to the Weibel magnetic fields. We then present results of an experiment that has allowed us to measure the spatiotemporal evolution of the magnetic fields using an ultrashort relativistic electron probe beam. Both the topology and the lifetime of the Weibel instability induced magnetic fields are in reasonable agreement with the simulations.