Rotational distribution in simultaneously excited electronic states of CH

A²Δ, B²Σ^? and C²Σ⁺ states of CH were excited in discharges through flowing C₂H₂ and C₂H₄ and in flames of C₂H₂. The rotational distributions in these states were determined from the measured integrated intensities of rotational lines for bands of A²Δ → X²Π, B²Σ^? → X²Π and C²Σ⁺ → X²Π. The A²Δ state exhibits a non-Maxwellian distribution while the B²Σ^? and C²Σ⁺ states show Maxwellian distributions. The non-Maxwellian distribution of the A²Δ state and the different rotational distributions in the three states are discussed.