Rovibrational distribution of H2 in low temperature plasma: the dependence on the plasma parameters

Fulcher-α band emissions were fitted using the Boltzmann distribution for the rotational and vibrational distribution of hydrogen molecules in MAP-II plasmas. The dependency of the rovibrational temperatures on the neutral pressure are explored in the cases of the helium discharges with H2 puff and pure H2 discharges. It was found that the rotational and vibrational temperatures increase with the electron temperatures in the experimental conditions studied. However, the opposite trend is predicted by our modeling, in which the newest cross section data are applied in the most important kinetic processes included in vibrational population balance based on the quasi-steady state and quasi-stationary approximation. The possible channels to cause the discrepancy are discussed; however, the physical mechanism behind remains un-discovered.