Intense long-lived magnetic wakes driven by relativistic laser pulses (Conference Presentation)

Abstract

The emergence of petawatt lasers focused on relativistic intensities enables all-optical laboratory generation of intense magnetic fields in plasmas, which are of great interest due to their ubiquity in astrophysical phenomena. We report our study of the generation of spatially extended and long-lived intense magnetic fields. We show that such magnetic fields, scaling up to the gigagauss range, can be generated by the interaction of petawatt laser pulses with relativistically underdense plasma. With three-dimensional particle-in-cell simulations, we investigate the generation of magnetic fields with strengths up to 10^10 G and perform a large multi-parametric study of the magnetic field in dependence on dimensionless laser amplitude a0 and normalized plasma density ne/nc. The numerical results yield scaling laws that closely follow derived analytical result B ≈ (a0ne/nc)^1/2, and further show a close match with previous experimental works. Furthermore, we show in three-dimensional geometry that the decay of the magnetic wake is governed by current filament bending instability, which develops similarly to von Kármán vortex street in its nonlinear stage. We envision interactions of relativistic electrons with studied intense magnetic wakes for probing of strong field quantum electrodynamics in magnetized plasmas. Our results pave the way towards the generation of intense, tunable, and long-lived magnetic fields in plasmas at various laboratory conditions, which lead to innumerable applications in plasma physics, fundamental physics, and laboratory astrophysics.