Knowledge Bank

The sodium D lines are found to excite iodine molecules to the electronic state $B3\Pi ou+(v\prime =15.16,17)$. The intensities of emission from these states and others produced by collisions with foreign gases have been determined photoelectrically. Spectral resolution has been adaquate to allow measurement of the collisional transfer of rotational as well as vibrational energy. Transfer from high rotational levels can be observed in the states with $v\prime =15$ and 17 which are excited by the sodium lines to levels with $J\prime >100$. The temperature dependence of the iodine self-quenching of fluorescence from each of the levels with $v\prime =15,16$, and 17 has been examined.