Coulomb Excitation of $^{124,126,128}$Sn(Z=50) on $^{12}$C, $^{27}$Al, and $^{50}$Ti: Approaching the N=82 Shell Closure via N=74,76,78

The determination of $<$0$_{1}\vert \vert $E2$\vert \vert $2$_{1}>$ matrix elements from the Coulomb excitation of $^{124,126,128}$Sn(Z=50) on a $^{12}$C target is presented. Furthermore, preliminary results are presented for the Coulomb excitation of $^{124,126,128}$Sn on $^{27}$Al and $^{50}$Ti targets, which, combined with the results from the $^{12}$C target, can provide an upper/lower limit for the 2$_{1}^{+}$ static quadrupole moments, Q(2$_{1})$ = 0.758 x $<$2$_{1}\vert \vert $E2$\vert \vert $2$_{1}>$ (expected to be $\approx $ 0). Indeed, accurate knowledge of 2$_{1}^{+}$ systematics, i.e., E(2$_{1})$, $<$0$_{1}\vert \vert $E2$\vert \vert $2$_{1}>$, and $<$2$_{1}\vert \vert $E2$\vert \vert $2$_{1}>$, are essential for testing consistency in models (e.g., deformation) at and near the neutron-rich N=82 shell closure.