Knowledge Bank

By using the 108 $\mu m$ and the 84 $\mu m$ lines of a $D2O$ laser, new magnetic resonances of the oxygen molecule have been observed. They have been identified as being transitions between the rotational levels (N = 17, J = 16) $\leftarrow$ (N = 15, J = 15) and (N = 21, J = 20) $\leftarrow$ (N = 19, J = 20) of the ground electronic and vibrational state. They confirm both the theory and the molecular constants presented in a previous paper by K. M. Evenson and M. Mizushima (Phys. Rev. A6, 2197 (1972)), where the experimental technique is also described.