Magnetically Induced Circular Polarization

Authors

• K.L. Stricklett, University of Nebraska - Lincoln
• D.J. Burns, University of Nebraska - LincolnFollow
• Paul Burrow, University of Nebraska - LincolnFollow

Document Type

Article

Date of this Version

December 1987

Comments

Published by American Physical Society. Phys. Rev. A 36, 5280 (1987). http://pra.aps.org. Copyright © 1987 American Physical Society. Permission to use.

Abstract

Helium atoms excited to an aligned (1s3d) ³D state are produced by electron impact parallel to a magnetic field. The initial alignment of the atomic state evolves into an orientation with finite angular momentum along the magnetic field direction and thus gives rise to a circularly polarized component in the (1s3d) ³D→(1s2p) ³P radiation propagating parallel to the magnetic field. Circular-polarization fractions of a few percent are observed, in general agreement with theory. The measured polarization fraction is found to be pressure dependent, indicating that secondary excitation and cascade processes must be included for a complete description.