ESTIMATION OF THE ABSOLUTE VALUES OF THE EFFECTIVE CROSS SECTIONS OF SECOND- ORDER COLLISIONS FOR MIXTURES OF SODIUM AND MERCURY VAPORS

Journal Article · Thu Aug 01 04:00:00 EDT 1963 · Izvestiya Akademii Nauk, Seriya Fizicheskaya (U.S.S.R.) For English translation see Bull. Acad. Sci. USSR, Phys. Ser. (Engl. Transl.)

OSTI ID:4157625

Frish, S E; Bochkova, O P

The study of the luminescence of Na + Hg vapor mixtures represents a useful tool for determining the absolute value of the effective cross section of second-order collisions. The Na atoms may be excited by 2 processes: first-order collisions with electrons and second-order collisions with excited Hg/sup */ atoms, assuming the Hg possesses only 1 excited state. Measurements were carried out with Na--Hg mixtures excited by a high-frequency discharge in a Mo glass tube providend with external electrodes. The largest second-order excitation may be e~pected at the 6P, 7S, and 6D levels of Na for collisions with Hg at the 6/sup 3/ P/sub 0/ state and at the 8S, 7D, 7F, 8P, 9S, 8D, 8F, and 9P levels for collisions with Hg atoms at the 6/sup 3/P/sub 1/ state. The absolute intensities of the secondary Na lines were measured photoelectrically by comparing them with the continiuous band spectrum used for calibration. It was found that the concentration of the excited Na atoms increases markedly when passing frori the luminescence of the pure Na atoms to that of Na + Hg. The population ot the 7S, 9S, 6D and 6P levels increased especially strong. The concentration of the normal Na atoms, N/sub o/(Na), determined by the anomalous dispersion method, was found to lie between 0.5 and 1.0 x 10/sup 13/ cm/sup -3/. The effective cross section of the second-order collisions was large even at excitation energies of a few hundred ev, making it possible to populate selectively the individual levels in the atoms and to obtain negative values for the absorption coefficients. (TTT)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-18-000767
• OSTI ID: 4157625
• Journal Information: Izvestiya Akademii Nauk, Seriya Fizicheskaya (U.S.S.R.) For English translation see Bull. Acad. Sci. USSR, Phys. Ser. (Engl. Transl.), Journal Name: Izvestiya Akademii Nauk, Seriya Fizicheskaya (U.S.S.R.) For English translation see Bull. Acad. Sci. USSR, Phys. Ser. (Engl. Transl.) Vol. Vol: 27; ISSN IANFA
• Country of Publication: Country unknown/Code not available
• Language: Russian

Related Subjects

ATOMIC MODELS
ATOMS
CONCENTRATION
CROSS SECTIONS
ELECTRONS
ENERGY LEVELS
EXCITATION
INTERACTIONS
LABORATORY EQUIPMENT
LUMINESCENCE
MEASURED VALUES
MERCURY
MIXING
PHOTOMETRY
PHYSICS
RADIATION EFFECTS
RADIOACTIVITY
SAFETY
SODIUM
SPECTRA
URANIUM
URANIUM COMPOUNDS
VAPORS