Population Inversion of Sodium Levels in a Mixture of Sodium and Mercury Vapors under Optical Excitation

S. É. Frish, O. P. Bochkova

S. Ya. Putninya, Zh. L. Shvegzhda, M. L. Yanson

S. Balushev, Norbert Leinfellner, Eugeny Korsunsky +1 more

I. M. Gurevich

I. P. Bogdanova, V. E. Yakhontova

M. Czajkowski, George M. Skardis, L. Krause

Collisional transfer of excitation from mercury to sodium was investigated using methods of sensitized fluorescence. A mixture of mercury and sodium vapors at low pressure was irradiated with Hg 2537 Å resonance radiation, producing a population of Hg(63P1) atoms whose inelastic collisions with ground-state sodium atoms resulted in a transfer of excitation energy to close-lying S, P, and D states in sodium. The subsequent decay of these states manifested itself in the emission of a sensitized fluorescent spectrum. Absolute intensity measurements on the components of the spectrum yielded 21 cross sections whose magnitudes range from 0.02 to 38.5 Å2 and which exhibit a pronounced resonance with ΔE, the energy defect between Hg (63P1) and the appropriate level in sodium.