  We measure the dependence of qubit phase coherence and surface spin induced
flux noise on inductor loop geometry. While wider inductor traces change
neither the flux noise power spectrum nor the qubit dephasing time, increased
inductance leads to a simultaneous increase in both. Using our protocol for
measuring low frequency flux noise, we make a direct comparison between the
flux noise spectrum and qubit phase decay, finding agreement within 10% of
theory. The dependence of the measured flux noise on inductor geometry is
consistent with a noise source correlation length between 6 and 400 um.
