Determination of the ionization cross sections of long lived excited helium, neon, and argon atoms by electron bombardment

Technical Report · Mon Oct 01 04:00:00 EDT 1973

OSTI ID:4939126

Shearer, W

Thesis. Submitted to Paris Univ., Orsay, France. An atomic beam crossed by two electron beams was used to measure the ionization cross section of long-lifetime excited helium, neon and argon atoms by electron bombardment. The results obtained concern both ionization from metastable states and ionization from excited Rydberg states. These results were obtained for ionizing electron energies of between 3 eV and 2 eV below the ionization potential of the ground- state atoms. The shapes of the curves obtained for the ionization cross sections of metastable states of these three gases are in good agreement with those obtained by Fite and Brackmann and those calculated using the Grysinski theory. The results demonstrate that a beam of metastable atoms produced by bombardment with electrons having energies similar or superior to the ground-state ionization potential of these atoms can contain a small proportion of atoms excited to the Rydberg state. The effect of such atoms becomes very important when the beam is to be used for experiments involving collisions between metastable atoms and other particles. (auth)

• Research Organization: CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Recherche et Analyse
• Sponsoring Organization: Sponsor not identified
• NSA Number: NSA-29-027679
• OSTI ID: 4939126
• Report Number(s): CEA-N--1663
• Country of Publication: France
• Language: French

Related Subjects

ARGON
ATOMS
COLLIDING BEAMS
CROSS SECTIONS
ELECTRON-ATOM COLLISIONS
EV RANGE 01-10
EV RANGE 10-100
EXCITED STATES
HELIUM
IONIZATION
LIFETIME
MEASURING METHODS
METASTABLE STATES
N60400* --Physics (Atomic & Molecular)--Collision Phenomena
NEON
SECONDARY EMISSION