Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

University of Arizona Press eBooks

COHERENCE AND ITS APPLICATION IN THE BEAM-FOIL LIGHT SOURCE

Chih‐Ting Liu, STANLEY BASHKIN

Published Feb 4, 2018• 0 citations
Publisher

Abstract

The beam-foil light source is shown to be very useful in spectroscopic work. Not only the lifetimes of highly excited, multiply charged atoms can be measured in a straightforward way, but also the fine-structure and hyperfine-structure separations and the Lande factors can be obtained due to the fact that the coherent excitations are created in the impulsive beam-foil collision. The theories suggested to explain the origin of coherence are presently incomplete.

DOI
10.2307/j.ctt2050vsn.9

Related papers

Interference Between Coherent Emissions in the Measurement of Atomic Lifetimes

J. H. Macek

It is pointed out that the (zero-field) oscillations seen in the decay curves for atoms excited by beam-foil collisions may be due to interference of light from different fine-structure levels; the interference can only be seen, however, if light of different polarizations is detected with different sensitivity.

Physical Review Letters•Jul 7, 1969•74 citations

The Spectroscopic Properties of the Ionic Beam Source

William S. Bickel

A relatively new spectroscopic source, consisting of a beam of high velocity, unidirectional and monoenergetic atoms and ions that have been electronically excited by a thin foil, is described. Special attention is directed toward the properties of spectroscopic interest; some of these properties include particle densities, source purity, operating parameters, and the nature of the radiation emitted. The application of the source to the study of atomic excited state lifetimes is described with specific emphasis on the techniques of obtaining quantitative data using spectrometers, photomultipliers, and interference filters Also included is a complete bibliography of work done up to the present date.

Applied Optics•Aug 1, 1967•29 citations

Fine Structure, Hyperfine Structure and Lamb Shift Measurements by the Beam-foil Technique

H. J. Andrä

A survey on high resolution experiments with atomic systems prepared by the beam-foil or beam-gas interaction is presented. RF-resonance, field-quenching, quantum-beat and level-crossing experiments are described in elementary terms whereas more advanced theoretical techniques are sketched for quantum beats in an appendix.

Physica Scripta•May 1, 1974•94 citations

Polarization and Collision-Induced Coherence in the Beam-Foil Light Source

C. H. Liu, STANLEY BASHKIN, D. A. Church

Polarization up to 15% has been detected in the decay of electronic levels in many-electron monatomic systems which were excited by the beam-foil method, the foil being tilted with its plane at 65\ifmmode^\circ\else\textdegree\fi{} to the particle velocity. Quantum beats were found even with an external magnetic field oriented parallel to the particle velocity, indicating that coherence is produced in the beam-foil interaction itself. Results are reported for various levels in He i, O ii, and Ar ii.

Physical Review Letters•Oct 21, 1974•21 citations

Electronic state alignment, orientation, and coherence produced by beam-foil collisions

D. A. Church

The cylindrically symmetric beam-foil collision produces excitation and alignment of atom and ion levels similar, but not identical, to that resulting at comparable energies from ion-atom or ion-molecule collisions. When the foil is tilted, the macroscopic change acts on the microscopic scale to produce coherent alignment and orientation of the excited levels. The maximum beam energy range bounding this interaction has not yet been defined. The dynamic interaction which produces these effects is currently not predicted by any theory, although the dynamics of the ions subsequent to the collision are well understood. Refinement of current experimental technique can be expected to better define the final foil surface. The beam-tilted-foil collision promises to be useful in the study of ionic structure via quantum beat, radio-frequency and level-crossing spectroscopy techniques, and may provide a useful probe for certain surface interactions. 4 figs, 48 refs.

•Jul 22, 1975•0 citations

Coherent Emission Light Source

Robert B. Griffiths, Robert Henry Dicke

A sharp, intense emission line may be obtained by use of resonance radiation coherently scattered from a collimated beam of atoms. The coherently scattered light may be separated from the exciting radiation by placing the atomic beam in one arm of a Mach-Zehnder interferometer or by diffraction from several parallel atomic beam pencils. The latter technique has been tested experimentally by observing hyperfine structure in light coherently scattered from a beam of sodium atoms.

Review of Scientific Instruments•Aug 1, 1957•5 citations
The beam-foil light source is shown to be very useful in spectroscopic work. Not only the lifetimes of highly excited, multiply charged atoms can be measured in a straightforward way, but also the fine-structure and hyperfine-structure separations and the Lande factors can be obtained due to the fact that the coherent excitations are created in the impulsive beam-foil collision. The theories suggested to explain the origin of coherence are presently incomplete.
A relatively new spectroscopic source, consisting of a beam of high velocity, unidirectional and monoenergetic atoms and ions that have been electronically excited by a thin foil, is described. Special attention is directed toward the properties of spectroscopic interest; some of these properties include particle densities, source purity, operating parameters, and the nature of the radiation emitted. The application of the source to the study of atomic excited state lifetimes is described with specific emphasis on the techniques of obtaining quantitative data using spectrometers, photomultipliers, and interference filters Also included is a complete bibliography of work done up to the present date.
Polarization up to 15% has been detected in the decay of electronic levels in many-electron monatomic systems which were excited by the beam-foil method, the foil being tilted with its plane at 65\ifmmode^\circ\else\textdegree\fi{} to the particle velocity. Quantum beats were found even with an external magnetic field oriented parallel to the particle velocity, indicating that coherence is produced in the beam-foil interaction itself. Results are reported for various levels in He i, O ii, and Ar ii.
The cylindrically symmetric beam-foil collision produces excitation and alignment of atom and ion levels similar, but not identical, to that resulting at comparable energies from ion-atom or ion-molecule collisions. When the foil is tilted, the macroscopic change acts on the microscopic scale to produce coherent alignment and orientation of the excited levels. The maximum beam energy range bounding this interaction has not yet been defined. The dynamic interaction which produces these effects is currently not predicted by any theory, although the dynamics of the ions subsequent to the collision are well understood. Refinement of current experimental technique can be expected to better define the final foil surface. The beam-tilted-foil collision promises to be useful in the study of ionic structure via quantum beat, radio-frequency and level-crossing spectroscopy techniques, and may provide a useful probe for certain surface interactions. 4 figs, 48 refs.