Probing ultrafast magnetic-field generation by current filamentation instability in femtosecond relativistic laser-matter interactions
G. Raj, O. Kononenko, M. F. Gilljohann, A. Doche, X. Davoine, C. Caizergues, Y.-Y. Chang, J. P. Couperus Cabadağ, A. Debus, H. Ding, M. Förster, J.-P. Goddet, T. Heinemann, T. Kluge, T. Kurz, R. Pausch, P. Rousseau, P. San Miguel Claveria, S. Schöbel, A. Siciak, K. Steiniger, A. Tafzi, S. Yu, B. Hidding, A. Martinez de la Ossa, A. Irman, S. Karsch, A. Döpp, U. Schramm, L. Gremillet, S. Corde
Abstract
This paper presents experimental measurements of the femtosecond timescale generation of magnetic field fluctuations exceeding 1 kT in relativistic laser-solid interaction, using a probe electron beam generated in a laser wakefield accelerator. Three-dimensional particle-in-cell simulations demonstrate that such fluctuations originate from the current filamentation instability arising at submicron scales around the irradiated target surface, and that they grow in a few tens of femtoseconds to amplitudes strong enough to broaden the angular distribution of the probe electron bunch.