Dimensionless corona temperature Θ ≡ kT_e/m_ec² as a function of the funnel half-opening angle (in degrees). Red curves assume that all gravitational power is dissipated in the hot corona (f_c = 1), while green curves correspond to f_c = 0.5, with the remaining power released as thermal radiation in the accretion flow. Solid lines assume a single-pass scattering probability of soft photons by the corona of 30%, dashed lines of 50%.