Figure 1

Angular distribution of elastic scattering of ${}^{16}\mathrm{O}$ on ${}^{28}\mathrm{Si}$ at $E_L=1503\mathrm{MeV}$, from Ref. 13. The data are linked to guide the eyes.Reuse & Permissions

Figure 2

Same as for Fig. 1, for the elastic scattering of ${}^{16}\mathrm{O}$ on ${}^{28}\mathrm{Si}$ at $E_L=55\mathrm{MeV}$, from Ref. 6.Reuse & Permissions

Figure 3

Same as for Fig. 1 for the elastic scattering of ${}^{12}\mathrm{C}$ on ${}^{28}\mathrm{Si}$ at $E_L=33.64\mathrm{MeV}$, from Ref. 7.Reuse & Permissions

Figure 4

Elastic scattering of ${}^{16}\mathrm{O}$ on ${}^{28}\mathrm{Si}$ at $E_L=75\mathrm{MeV}$. The points plot $\frac{1}{2}{\left(d{\sigma }_R∕d\Omega \right)}^{1∕2}\left(d\sigma ∕d{\sigma }_R–1\right)$ as a function of $\theta$ (log scale), using for $d\sigma ∕d\Omega$ the experimental data. The broken lines have been drawn through the points to localize the extrema of the fast oscillation. The solid line has been obtained by searching the value of $\mid f_n\left(0\right)\mid$ such that $\mid f_n\left(0\right)\mid \mid J_0\left(l_g\theta \right)\mid$ envelopes the rapid oscillations (see text).Reuse & Permissions

Figure 5

Same as for Fig. 4 for the elastic scattering of ${}^{12}\mathrm{C}$ on ${}^{28}\mathrm{Si}$ at $E_L=65\mathrm{MeV}$.Reuse & Permissions

Figure 6

(Color online) The Rutherford trajectories corresponding to the Coulomb scattering of ${}^{16}\mathrm{O}$ on ${}^{28}\mathrm{Si}$, $E_L=75\mathrm{MeV}$. The trajectories are collimated by a circular hole cut on an opaque screen. As seen, the only trajectories scattered forward are those passing near the edge of the hole (see text).Reuse & Permissions

Figure 7

Comparison between the numerical evaluation of ${\mid f_n\left(\theta \right)\mid }^2$ with $f_n\left(\theta \right)$ as given by Eq. (7) (full curve) and that of the approximate expression (8) (broken curve).Reuse & Permissions

Figure 8

The points are the experimental data shown in Figs. 1, 2, 3 plotted versus the variable $x=l_g\theta$ for forward scattering or $x=l_g\left(\pi -\theta \right)$ for backward scattering. The data are linked to guide the eyes. The lower curve is a plot of the expression $J_0^2\left(x\right)$ in the domain where it reproduces the angular dependence of the evelopes shown in Figs. 4, 5 (see text). The location of the three first zeros of $J_1^2\left(x\right)$ are indicated. A striking feature of these plots is the experimental evidence for the “$180°$ out of phase” rule between the oscillation due to shadow effects (upper curve) and those due to surface effects (lower curves).Reuse & Permissions