Figure 2

Three-dimensional presentation of the triple-differential cross section for single ionization of Ar $\left(3p\right)$ by 70.8 eV electron impact as a function of the emission angle of an electron with kinetic energy $E_2=3\mathrm{eV}(\pm 1.0\mathrm{eV})$ and different projectile scattering angles $\left({\theta }_1\right)$. (a) and (b) ${\theta }_1=-8^{\circ }(\pm 1.5^{\circ })$, (c) and (d) ${\theta }_1=-{10}^{\circ }(\pm 2.0^{\circ })$, (e) and (f) ${\theta }_1=-{15}^{\circ }(\pm 2.5^{\circ })$, (g) and (h) ${\theta }_1=-{20}^{\circ }(\pm 3.0^{\circ })$, (i) and (j) ${\theta }_1=-{25}^{\circ }(\pm 3.0^{\circ })$, and (k) and (l) ${\theta }_1=-{30}^{\circ }(\pm 3.5^{\circ })$. Left column: experiment. Right column: $B$-spline $R$-matrix with pseudostates (BSR) theory.