Fig. 4: Simulation results.
From: A multi-MeV alpha particle source via proton-boron fusion driven by a 10-GW tabletop laser
a Profile of the preplasma modeled by hydrodynamic simulation in terms of electron density Ne (density normalized to critical density Nc in the colorbar). The original target surface is located at x = 0 μm. The snapshot is captured at the moment of 14 ns after the prepulse arrival and the corresponding data are used as an input for the particle-in-cell simulation at the time 0 fs. b Transverse magnetic field Bz during the interaction of the peak laser intensity (main pulse) with the target modified by the picosecond prepulse, showing the incidence and reflection directions of the main pulse (in terms of normalized dimensionless field a0) ~15 µm away from the original target surface. A contour of the preplasma having critical density depicted in black is added to the figure. c Energy distribution of simulated protons in the forward (into the target, red dashed line) and backward (away from the target, blue solid line) directions.
