Fig. 9
From: Generation of giga-electron-volt proton beams by micronozzle acceleration
Maximum proton energy \(\mathcal {E}_{\textrm{max}}\) and the laser-to-proton conversion efficiency \(\eta _c\) measured at \(t=1\) ps as a function of the laser pulse width \(\tau _L\) under different applied laser intensities \(I_L\). All the target and laser conditions are the same as those for the blue circles in Fig. 8.
