Knowledge Bank

We have recorded $N2-$ and Ar-broadened spectra of the allowed P-and branch manifolds for $J\le 10$ in the $\nu 3$ band of $CH4$ from the Doppler limit to $\sim 67kPaatT=295K$ using a tunable difference-frequency laser spectrometer. The broadening coefficients and shifts and Dicke narrowing will be compared with prior laser measurements in the Q branch of this $band1$ as well as previous FTIR measurements in the P and R $branches2$. We will also address the question of line mixing between the overlapping tetrahedral components in a given blended J manifold as reported by the NASA Langley $group3$.