Possible values of red giant wind particle number density scale and plasma temperature (n₀, T₀) (solid lines) for the 2016 VLA (top panels) and 2024 ALMA spectra (bottom) of T CrB, for an assumed stellar radius of R = 54 R_⊙ (left), R = 70 R_⊙ (middle), and R = 100 R_⊙ (right). The regions allowed by the lower limit on the turnover frequency are in white. Inside the shaded regions, the lines of (n₀, T₀) solutions are shown as dashed in order to indicate that they do not respect the constraint set by the lower limit on the turnover frequency and are thus not physical. The top axis indicates stellar mass-loss rates corresponding to the number density, n₀. A fiducial frequency, ν₀ = 30 GHz, whose choice little alters the result compared to other systematics, was used to compute T₀(n₀) from equation (6).