Steady-state quantities describing the disk magnetization for the fiducial model. Panel a: mid-plane magnetic fields strength as a function of radius. The solid black line corresponds to B, the optimalr.m.s. magnetic field strength that is required for the MRI activity to be at the maximal efficiency as permitted by Ohmic resistivity and ambipolar diffusion (Sect. 3.2). The dotted red line corresponds to , the threshold for the magnetic field strength from and above which the MRI-driven turbulence with such a field strength is prohibited by ambipolar diffusion, given the ambipolar condition (β > β_min) of our active MRI criteria (Sect. 3.1). The dash-dotted black line corresponds to , the equipartition field. The gray shaded area corresponds to the radial locations within the mid-plane dead zone. Panel b: Radial profiles for the β-plasma parameter defined from the optimal r.m.s. magnetic field strength B (Sect. 3.1), for the mid-plane (solid line), z = 1 H_gas (dash-dotted line), z = 2 H_gas (dotted line), and z = 3 H_gas (dashed line).