Editing Plasma afterglow (section)

A '''plasma afterglow'''  (also '''afterglow''') is the radiation emitted from a [[plasma (physics)|plasma]] after the source of ionization is removed.<ref>{{cite web |url=http://plasmadictionary.llnl.gov/terms.lasso?-MaxRecords=1&-SkipRecords=6&-SortField=Term&-SortOrder=ascending&page=detail |title=Plasma Dictionary |publisher=Lawrence Livermore National Laboratory |accessdate=2014-08-12 |url-status=dead |archiveurl=https://web.archive.org/web/20140817123607/http://plasmadictionary.llnl.gov/terms.lasso?-MaxRecords=1&-SkipRecords=6&-SortField=Term&-SortOrder=ascending&page=detail |archivedate=2014-08-17 }}</ref>
The external [[electromagnetic field]]s that sustained the plasma glow are absent or insufficient to maintain the discharge in the afterglow.  A plasma afterglow can either be a temporal, due to an interrupted (pulsed) plasma source, or spatial, due to a distant plasma source.  In the afterglow, plasma-generated species de-excite and participate in secondary chemical reactions that tend to form stable species. Depending on the gas composition, super-elastic collisions may continue to sustain the plasma in the afterglow for a while by releasing the energy stored in [[rovibronic excitation|rovibronic]] degrees of freedom of the atoms and molecules of the plasma. Especially in molecular gases, the plasma [[chemistry]] in the afterglow is significantly different from the plasma glow. The afterglow of a plasma is still a plasma and as thus retains most of the properties of a plasma.