Fig. 1: 3D particle-in-cell simulations of SM-LWFA.
From: Plasma electron acceleration driven by a long-wave-infrared laser
a Electron density ne(z) profile (black dashed curve) of unperturbed, fully-ionized 2 mm gas jet with ne = 5 × 1017 cm−3 plateau and 0.25 mm exit ramp used for simulations. Vacuum field envelopes of right-propagating 2 J, 4 ps (0.5 TW, yellow) and 4 J, 2 ps (2 TW, blue) pulses, which vacuum-focused at z = 0.1 mm (marked by star), are shown at z = 1.7 mm. Remaining panels: 2D wake profiles δne(x, z)/ne when b 0.5 TW or d 2 TW pulses reach z = 1.7 mm, and simultaneous normalized 2D electron momentum profiles pz(x, z)/mec for c 0.5 TW and e 2 TW excitation, i.e. below and above self-injection threshold, respectively. Black curves in (c) and (e): longitudinal electric field Ez(z) profiles on the laser propagation axis, referenced to right-hand vertical scales. f Projection onto a plane of ≥10 MeV electrons at a later instant, after the 2-TW-laser-driven wake accelerated them into vacuum.
