RADIATIVE DECAY CONSTANTS OF H-2 FULCHER BANDS

The radiative decay constants corresponding to the Fulcher bands of the H2 molecular spectrum are obtained using pulsed-electron beam techniques. Data in the range ∼1.8 to 2.8×107 s -1 are obtained at 25 eV incident electron energy for the d 3πu → a 3Σg + (ν′, ν″)Q(K) and k 3πu → a 3Σg+ (ν′,ν″) Q(K) rotational lines with K = 1,2,3 and ν′ =.0,1,2,3,→ν″ = 0,1,2,3. Additional measurements of the d 3πu→a 3Σg+(0,0)Q1 rotational line intensity indicate the presence of a two-mode decay over the energy range 50-300 eV. The long-lived decay component, identified as radiative cascade from upper levels, contributes ∼15% to the total d 3πu(ν′ = 0) population. © 1978 American Institute of Physics.