Ionizing Collisions of Metastable Helium Atoms in Gases

Journal Article · Mon Jan 01 04:00:00 EST 1962 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.1732469· OSTI ID:4824504

Sholette, W. P. ^[1]; Muschlitz, E. E. ^[1]

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1. Univ. of Florida, Gainesville, FL (United States). Dept. of Chemistry

Ionization cross sections for collisions of metastable 2³ S and 2¹ S He atoms in Ar, Kr, Xe, H₂, O₂, N₂, and CO were measured using a thermal-energy atomic beam in which a fraction of the helium atoms are excited by electron bombardment. Ions produced in these gases by elastic collisions were detected at a metal electrode, and unscattered or elastically scattered metastable atoms were detected by observing the electrons they ejected from metal surfaces. Within the experimental error of the measurements, the cross sections for the triplet and singlet states of helium were the same in all cases except that of H₂. For the rare gases, the results indicated that the size of the struck particle is the primary factor in determining the cross section for ionization, rather than the energy excess. Lastly, In the case of the diatomic molecules an additional consideration, that of the number and type of ionization processes possible, was also found to be important.

• Research Organization: Univ. of Florida, Gainesville
• Sponsoring Organization: USDOE
• Contributing Organization: National Science Foundation (NSF)
• NSA Number: NSA-16-026238
• OSTI ID: 4824504
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 12 Vol. 36; ISSN JCPSA6; ISSN 0021-9606
• Publisher: American Institute of Physics (AIP)
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ARGON
ATOMS
BEAMS
CARBON MONOXIDE
COLLISIONS
CROSS SECTIONS
DETECTION
ELECTRODES
EXCITATION
GASES
HELIUM
HYDROGEN
INERT GASES
IONIZATION
IONS
IRRADIATION
KRYPTON
MEASURED VALUES
METALS
METASTABLE STATES
MOLECULES
NITROGEN
OXYGEN
PHYSICS
RARE GASES
XENON