Ionization and excitation of hydrogen and helium Rydberg atoms by microwaves

Conference · Sun Apr 01 00:00:00 EST 1990 · AIP Conference Proceedings (American Institute of Physics); (USA)

OSTI ID:6229640

Moorman, L; Sauer, B E; Yoakum, S; Koch, P M ^[1]; Galvez, E J ^[2]; van de Water, W; van Leeuwen, K A.H. ^[3]

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1. Physics Department, State University of New York, Stony Brook, NY (USA)
2. Department of Physics and Astronomy, Colgate University, Hamilton, NY (USA)
3. Physics Department, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (The Netherlands)

We have used the interaction of hydrogen Rydberg atoms with microwave fields to study multiphoton ionization. The minimum number of photons absorbed in the experiments ranges from about 300 to only 15. A brief overview is given of the extensive theoretical work that is under development to explain experimental data, including various observed structures. Similarly we report on ionization of helium Rydberg atoms, qualitatively explained in terms of a static picture. Finally we show selective excitation of He triplet {ital s}-state to higher angular momentum states, via absorption of several photons from the field. Using the Floquet method a close analogy between the microwave problem and slow atomic collisions can be made. Sharp resonant structures in the spectra can be linked to individual avoided crossings of calculated Floquet quasi-energy curves. Our theory that exploits a separation of timescales explains very well the positions, depths, and shapes of the observed structures, but a discrepancy still remains concerning their widths.

• OSTI ID: 6229640
• Report Number(s): CONF-8907183-; CODEN: APCPC; TRN: 91-003076
• Journal Information: AIP Conference Proceedings (American Institute of Physics); (USA), Vol. 204:1; Conference: Aspects of electron-molecule scattering and photoionization conference, New Haven, CT (USA), 22-25 Jul 1989; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
HELIUM
MULTI-PHOTON PROCESSES
HYDROGEN
EXCITATION
EXPERIMENTAL DATA
FLOQUET FUNCTION
IONIZATION
MEASURING METHODS
MICROWAVE RADIATION
DATA
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY-LEVEL TRANSITIONS
FLUIDS
FUNCTIONS
GASES
INFORMATION
NONMETALS
NUMERICAL DATA
RADIATIONS
RARE GASES
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena