Knowledge Bank

In addition to the narrow resonances from the hyperfine components of the particular rotational line of the $NO2 2B2$ state excited, a broad resonance appears in the ORDER $spectrum.1$ This resonance has a pressure independent lifetime of $0.4\pm 0.1$ us which is attributed to the ``lifetime’’ of a non-stationary state prepared by the excitation source. This lifetime corresponds to the lifetime $\tau o$ introduced in a simple model of the dephasing and radiative lifetimes of $NO2.2$ According to this model the dephasing lifetime, $\tau c$, depends on $\tau o$ and the rotational quantum number N as follows: \begin{equation} \tau_{c} = \tau_{o} (2N + 1) \end{equation} Dephasing times measured in the Hanle effect are well predicted by this $model.3$