CROSS SECTIONS FOR THE DE-EXCITATION OF HELIUM METASTABLE ATOMS BY COLLISIONS WITH ATOMS

Journal Article · Mon Oct 01 04:00:00 EDT 1962 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.128.206· OSTI ID:4766856

Benton, E E; Ferguson, E E; Matsen, F A; Robertson, W W

The lifetimes of metastable helium atoms He(2 /sup 3/S) and He(2 /sup 1/ S) were measured by a time-resolved optical absorption technique in the afterglow of a pulsed helium discharge at 10-mm pressure with small concentrations of various impurity gases added. The following deexcitation cross sections in units of 10/sup -16/ cm/sup 2/ have been determined for He(2 /sup 3/S): Ne--0.28, Ar-- 6.6, Kr--10.3, Xe--13.9, N/sub 2/--6.4, and H/sub 2/--6.0. The uncertainties are estimated to be plus or minus 20% for the rare gases and plus or minus 50% for the molecular gases. He(2 /sup 1/S) cross sections were measured to be N--4.1, Ar--55, Kr--64, and Xe--103, all times 10/sup -16/ cm/sup 2/. The neon cross section is believed reliable to plus or minus 20% but the remaining singlet cross sections may be too high by as much as a factor 2 or 3. The cross sections refer to de-excitation by ionizing collisions except in the case of neon where neon excitation occurs. Competing destruction processes render the singlet cross- section analysis somewhat uncertain except in the case of neon. (auth)

• Research Organization: Univ. of Texas, Austin
• NSA Number: NSA-16-030972
• OSTI ID: 4766856
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 128; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
ARGON
ATOMIC MODELS
ATOMS
COLLISIONS
CROSS SECTIONS
EXCITATION
HELIUM
IMPURITIES
IONIZATION
KRYPTON
LIFETIME
MEASURED VALUES
NEON
NITROGEN
OPTICAL SYSTEMS
PHYSICS
STABILITY
XENON