2D Imaging of Anti-relaxation Coating Quality Using Regionally Specific Hyperfine Polarization

We show that the hyperfine polarization in the vicinity ($\sim 10^{-5}\,\rm cm$) of cell surfaces can be used as a novel way to quantify and map the regional surface property inside optical pumping cells. In silicone-coated cells our method allows us to image the regional quality of the coatings, revealing for the first time the existence of areas that have strikingly different qualities.