Collisional phenomena between electrons and high Rydberg atoms
Highly excited (Rydberg) atoms are produced and can exist for significant periods of time in various plasma environments. It is necessary to know cross sections for the various collision processes involving these atoms if a complete understanding of the physics of these environments is to be attained. The experimental investigation of collisional phenomena between high Rydberg sodium atoms and electrons is described in this thesis. A fraction of the atoms in a ground state sodium beams is opticaly excited (using lasers) to well-defined, high Rydberg states (principal quantum numbers chosen around 40). Subsequent to their production the Rydberg atoms are allowed to interact with 25 eV electrons for a specified time interval following which the collision products are detected. The electrons are produced in a beam which is crossed at right angles with the sodium beam. Important collision processes are (1) electron impact ionization of the Rydberg atom, and (2) electron-Rydberg atom interactions in which the quantum state of the atom is changed (state changing collisions). Results are presented for an observed state changing process which is identified as angular momentum state changing only (no change in the value of the principal quantum number). Cross sections for this process are measured to be 10/sup -10/ to 10/sup -9/ cm/sup 2/. Problems encountered during the work which prevented the measurement of eletron impact ionization cross sections are discussed. In the course of the work two other topics required study: (1) the process of electric field ionization of Rydberg atoms (used to detect the atoms), and (2) the effects of background (300 K) radiation (from the chamber walls, for example) on Rydberg atoms. Results of these studies are also presented.
- Research Organization:
- Rice Univ., Houston, TX (USA)
- OSTI ID:
- 5421322
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ELECTRON-ATOM COLLISIONS
SODIUM
ANGULAR MOMENTUM
ATOMIC BEAMS
COLLIDING BEAMS
CROSS SECTIONS
ELECTRON BEAMS
ENERGY LEVELS
IONIZATION
LASERS
RYDBERG CORRECTION
ALKALI METALS
ATOM COLLISIONS
BEAMS
COLLISIONS
CORRECTIONS
ELECTRON COLLISIONS
ELEMENTS
LEPTON BEAMS
METALS
PARTICLE BEAMS
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena