Convergence of the helium absorption spectrum with respect to the number of rays used in the RT calculations. The top panel shows the in-transit spectrum at orbital phase φ = 0, while the bottom panel shows the pre-transit spectrum at φ = −0.024. Light gray vertical dotted lines mark the nominal wavelengths of the He I 10 833 Å triplet. In the in-transit case, the spectrum converges quickly, with little change beyond N_rays > 300. However, the pre-transit configuration, which probes more extended and lower-density regions, requires a higher number of rays to achieve convergence. For this study, all spectra were computed using N_rays ≈ 1000.