V.D321 — Silk Damping at NLO

ℓ_D(NLO) = ℓ₁ × κ_D/κ_B = 220.02 × 5.655 = 1244.1 at +71 ppm. κ_D/κ_B ratio exact at all NLO orders. Improved from LO +2573 ppm.