  The extended $R^{(2)}_{\Psi_{m}}(\Delta S_{2})$ correlator is presented and
examined for its efficacy to detect and characterize the quadrupole charge
separation ($\Delta S_{2}$) associated with the purported Chiral Magnetic Wave
(CMW) produced in heavy-ion collisions. Sensitivity tests involving varying
degrees of proxy CMW signals injected into events simulated with the
Multi-Phase Transport Model (AMPT), show that the $R^{(2)}_{\Psi_{m}}(\Delta
S_{2})$ correlator provides discernible responses for the background- and
CMW-driven charge separation. This distinction could aid identification of the
CMW via measurements of the $R^{(2)}_{\Psi_{2}}(\Delta S_{2})$ and
$R^{(2)}_{\Psi_{3}}(\Delta S_{2})$ correlators, relative to the second-
($\Psi_2$) and third-order ($\Psi_3$) event planes. The tests also indicate a
level of sensitivity that would allow for robust experimental characterization
of the CMW signal.
