Characteristics of vibrational temperature of hydrogen molecules in detached plasma

The ground-state vibrational temperature of hydrogen molecules, Tvib, is observed in detached plasma using a VUV spectrometer on a linear plasma device, TPD-SheetIV. Tvib was deduced by applying the corona equilibrium model by using the electron impact excitation rate and the spontaneous emission coefficient, taking into account the cascade contribution of E,F1Σg+ and the radiation trapping. Tvib can be found which results in a fit to the observed relative intensities of VUV spectrum in the range from 90 to 150nm. With increasing gas pressure P, Tvib gradually decreases from 5000 to 3000K and remains nearly constant at around 1000K in detached plasma at discharge current of 50A.