Compton Scattering Cross Section Measurement in Hall D at Jefferson Lab

The PrimEx-eta fixed-target experiment in Hall D at Jefferson Lab (E12-10-011\footnote{Spokespersons: A. Gasparian (contact), L. Gan, I. Larin, A. Somov}) will measure the $\eta\rightarrow\gamma\gamma$ decay width using the Primakoff method with a projected uncertainty of 3.2$\%$. In order to achieve this goal, Compton scattering from the atomic electrons in the target is being used as a reference process. Because of its similar kinematics to the $\eta\rightarrow\gamma\gamma$ decay, the total Compton scattering cross section can be measured using the same experimental configuration as the $\eta$ decay width measurement. Consequently, it can be used to verify the systematic uncertainties for the $\eta$ decay width measurement and monitor the luminosity, detection efficiency, and overall experimental stability. The first phase of the PrimEx-eta data was collected in 2019, corresponding to roughly one-third of the total proposed statistics. In this talk, I will discuss the preliminary results for the total Compton scattering cross section measured on a $^{9}$Be target. This will provide the first experimental data for Compton scattering in the energy range 6-11 GeV.