Collisional Relaxation Of Low-Lying Electronically Excited-States Of Uranium - F3ds2(5k05) And (5l70)A)

Laser induced fluorescence techniques have been used to measure the rates of electronic relaxation of atomic uranium in a beam‐gas scattering apparatus. Cross sections for the collisional deactivation of the U f3ds2(5K50) and (5L70) states by H2, D2, HD, CH4, N2, and CO at room temperature are reported. Upper limits for quenching cross sections with He were also obtained. Relaxation of these uranium metastables by molecular hydrogen (H2, D2, and HD) and methane appears to proceed by resonant electronic‐to‐rotational or electronic‐to‐vibration/rotational energy transfer processes.