FIP effect

FIP effect (. From English f irst i onization p otential , "first ionization potential ") is called the observation that the solar wind and the solar corona a different chemical composition have as the photosphere originate from which they actually: elements having a first ionization potential is less than about 10  eV , are up to six times as frequent in the solar wind and the corona as elements with ionization potentials greater than 10 eV. In the fast solar wind the FIP effect is only weak or disappears completely, in slow solar wind it is very pronounced.

The cause of the FIP effect is not yet understood. Presumably it plays a role that elements with an ionization potential of less than 10 eV are ionized in the chromosphere at the prevailing temperatures, so that the FIP effect causes a fractionation between ionized and neutral elements.

literature

Constraints on the FIP mechanisms from solar wind abundance data : Fröhlich, C .; Huber, M .; Solanki, SK; von Steiger, Springer-Verlag GmbH, Heidelberg, Reprinted from SPACE SCIENCE REVIEWS, ISBN 978-0-7923-5496-3