Coherence structure of D1 scattering. Issue Volume 10:Issue S305(2014) (24th July 2015)

• Record Type: Journal Article
• Authors: Stenflo, Jan Olof
• Editors: Nagendra, K. N.; Bagnulo, S.; Centeno, R.; Martínez González, M. J.
• Is Part Of: Proceedings of the International Astronomical Union. Volume 10:Issue S305(2014)
• Page Start: 136
• Page End: 145
• Publication Date: 2015-07-24
• Subjects: line: profiles, -- methods: laboratory, -- atomic processes, -- polarization, -- radiation mechanisms: general, -- scattering, -- Sun: atmosphere; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921315004664
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: The extensive literature on the physics of polarized scattering may give the impression that we have a solid theoretical foundation for the interpretation of spectro-polarimetric data. This theoretical framework has however not been sufficiently tested by experiments under controlled conditions. While the solar atmosphere may be viewed as a physics laboratory, the observed solar polarization depends on too many environmental factors that are beyond our control. The existence of a symmetric polarization peak at the center of the solar Na D1 line has remained an enigma for two decades, in spite of persistent efforts to explain it with available quantum theory. A decade ago a laboratory experiment was set up to determine whether this was a problem for solar physics or quantum physics. The experiment revealed a rich polarization structure of D1 scattering, although available quantum theory predicted null results. It has now finally been possible to formulate a well-defined and self-consistent extension of the theory of quantum scattering that can reproduce in great quantitative detail the main polarization structures that were found in the laboratory experiment. Here we give a brief overview of the new physical ingredients that were missing before. The extended theory reveals that multi-level atomic systems have a far richer coherence structure than previously believed.