The generalized stokes parameters: Relativistic effects in electron-atom collisions

Journal Article · Wed May 01 04:00:00 EDT 1996 · Bulletin of the American Physical Society

OSTI ID:394131

Zeman, V; Mceachran, R P; Stauffer, A D; Strivastava, R

In the non-relativistic fine-structure approximation the generalized STU-parameters adhere to various simple relationships. The recently defined generalized Stokes parameters also follow simple relationships in this approximation. The authors derive these relationships by extending their previous calculations of the differential Stokes parameters for electron impact excitation of quasi one-electron atoms. They find that the generalized Stokes parameters are very sensitive to relativistic effects and, along with the generalized STU-parameters, provide experimenters with a second method by which to measure these effects. Of particular interest is Q{sup +{minus}+{minus}}=(I{sup {up_arrow}}-I{sup {down_arrow}})/(I{sup {up_arrow}}+I{sup {down_arrow}}) where I is the photon intensity from the decay of the state excited by transversely polarized electrons in the positive ({up_arrow}) or negative ({down_arrow}) directions. The values of Q{sup +{minus}+{minus}} for various fine-structure states bear simple relationships to one another in the fine-structure approximation. Examples of calculations using the relativistic distorted-wave approximation will be given.

• OSTI ID: 394131
• Report Number(s): CONF-9605105--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 3 Vol. 41; ISSN BAPSA6; ISSN 0003-0503
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COULOMB EXCITATION
ELECTRON-ATOM COLLISIONS
RELATIVISTIC RANGE
STOKES PARAMETERS