Experimental Determination of the Free Neutron F$_{2}$ at Large Bjorken-x: The BONuS12 Proton Recoil Detector

While the proton F$_{2}$ structure function has been studied extensively through inelastic electron-proton scattering, much less is known about neutron structure due to the unavailability of high density, free neutron targets. The BONuS12 experiment was proposed to measure the neutron F$_{2}$ on a nearly free neutron within a weakly bound deuteron target via the spectator tagging method. Tagging the slow backward moving spectator protons minimizes both off-shell and final-state interaction effects with the measured proton momentum used to correct for the initial-state momentum of the struck neutron. The recoil detector will be used to detect spectator protons with momenta 70 $<$ P$_{s}$ $<$ 150 MeV/c and the CEBAF Large Acceptance Spectrometer (CLAS12) to detect the scattered electrons. In this talk, I will present the design and construction of the recoil detector (RTPC), which was lead by Hampton University.