Down Quark Polarization Measurements with CLAS12

Perturbative Quantum Chromodynamics (pQCD) predicts that the spin of a valence quark will align with the net spin of the nucleon if the quark carries most of the nucleon’s momentum.  Previous measurements have yet to clearly illustrate this prediction for the down quark in the proton.  A comprehensive program to measure deep inelastic electron scattering using a polarized electron beam and polarized proton and deuteron  targets will be performed using the recently upgraded facilities at Jefferson Lab.  This program will facilitate the extraction of the down quark polarization within a proton to a kinematic regime where the struck quark may carry up to 80% of the proton's momentum.  The measurement will use a combination of the accelerator's 12 GeV polarized electron beam, the upgraded detector system, and a new longitudinally polarized target in Jefferson Lab's Hall B.   The anticipated precision of these measurements and their potential as a test of the pQCD prediction above will be presented.