Fig. 10
From: Generation of giga-electron-volt proton beams by micronozzle acceleration
Summary on the angular distributions of the proton beams, \(dN/d\theta\), at different laser intensities, where the angle \(\theta\) is measured with respect to the x-axis. The coherent results for the maximum proton energy \(\mathcal {E}_p\) are given in Fig. 8 as the blue circles. The red squares on the vertical plane denote the angular divergences (FWHM), \(\Delta \theta (I_L)\), obtained from the individual curves of \(dN/d\theta\).
