Measurement of Vibration-Vibration Energy Transfer Time in HF Gas

Abstract

An experiment which yields a value of 6.6×10⁵ Torr⁻¹ sec⁻¹ for the vibration‐vibration decay rate of the v=2 state in HF gas is described. The technique involves observation of the rise time of the HF v=2 vibrational fluorescence emanating from a gas sample pumped with a HF laser operating on a v=1→v=0 transition. An analytic model which predicts the temporal behavior of the HF v=1 and collisionally populated v=2 vibrational levels is also described. This model predicts an apparent decay rate of the v=2 fluorescence, which is twice that for v=1. Experimental measurements confirm this prediction.