Spectrometer Optics Calibration for Jefferson Lab $g_2^p$ Experiment

The proton spin-dependent structure function $g_2^p$ in the resonance region has been measured in a recent experiment at Jefferson Lab's Hall A. The goal of this experiment is to determine the $g_2^p$ structure function in the $Q^2$ region of 0.02-0.20 GeV$^{2}$ by using a transversely polarized NH$_3$ target. The Hall A High Resolution Spectrometers (HRS) were used to provide an inclusive measurement of scattered electrons at $5.69^{\circ}$. A pair of septum magnets were used to bend the $5.69^{\circ}$ scatted electrons into the $12.5^{\circ}$ spectrometers. A full optics calibration of the spectrometer is required to extract the kinematic quantities at the interaction vertex. However, the calibration procedure is challenging due to the complications from the strong transverse target field (2.5 T and 5.0 T) and the varied field configurations of the septum magnets. The details of the optics calibration and the progress will be described in this talk.