Knowledge Bank

Fifty-four transitions of the fundamental band of CH have been measured using an IR tunable difference frequency system. CH was generated in a dc discharge through 1 torr He and a few millitorr of $CH4$. Zeeman modulation was used to observe low J transitions, while amplitude discharge modulation was necessary at higher J. A combined fit of these data, microwave-optical double resonance and microwave data yielded values for the band origin, the spin-orbit constant, rotational constants, spin-rotation constants, and lambda-doubling constants for both $v=0$ and $v=1$ as well as magnetic hyperfine constants for $v=0$.