Lifetime Measurements of Metastable States in Molecular Nitrogen

The molecular beam method for the measurement of the lifetime of metastable states has been improved by the introduction of differential pumping, control of the energy of the bombarding electrons, and use of a movable detector. A lower limit of 10—2 sec is obtained for the lifetime of the A 3Σu+ state of N2, in closer agreement with spectroscopic observations than the previous work of Muschlitz and Goodman. The measured value of the lifetime of the a 1IIg state of N2 is (1.7±0.3)×10—4 sec. Some new observations on metastable states of the rare gas atoms, A, Kr, and Xe; CO and H2 are mentioned briefly.