Fig. 2
From: Generation of giga-electron-volt proton beams by micronozzle acceleration
Distributions of the lateral electric fields \(E_y\) (compare Fig. 1) at t = 110 fs without (left) and with (right) the nozzle, respectively, where the peak laser intensity of \(I_L = 3 \times 10^{21}\) W/\(\hbox {cm}^2\), the pulse width of \(\tau _L=100\) fs, and the spot size of 10 \(\upmu\)m (FWHM) are employed. The nozzle-head structure works to amplify the energy fluxes of both laser light and hot electrons in terms of the nozzle-head.
