Figure 3.

${\nu }_{x,y}$ versus angle of incidence θ, calculated for 500 eV Ar${}^{+}$ irradiation of Si with $j=1\times {10}^{15}$ cm${}^{-2}$ s${}^{-1}$, $a=2$ nm, $\sigma =0.8$ nm, $\mu =0.4$ nm, and $Y=2$.