On the theoretical significance of density measurements in XUV flare kernels

Abstract

view Abstract Citations (5) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the theoretical significance of density measurements in XUV flare kernels. Brown, J. C. ; Nakagawa, Y. Abstract Current methods of diagnosis of soft X-ray kernels in flares often indicate electron densities in excess of 1 trillion per cu cm. In particular, use of the forbidden-to-intercombination line-intensity ratio in He-like ions leads to electron densities of at least 10 to the 14th power per cu cm. The physical implications of these high densities are discussed in terms of the energetics and dynamics of flare mechanisms, and it is concluded that an electron density of around 10 to the 14th power per cu cm is impossible. Possible sources of error in the forbidden-line method are then discussed, and it is concluded that neither radiation nor plasma turbulence can explain the high-density results, though each can play a role in some transition rates. This leaves transient ionization equilibrium as the only possible explanation and implies that kernels represent direct evidence of a dynamic field-dissipation process in flares. Publication: The Astrophysical Journal Pub Date: November 1978 DOI: 10.1086/182815 Bibcode: 1978ApJ...225L.153B Keywords: Density Measurement; Far Ultraviolet Radiation; Radiant Flux Density; Solar Flares; Solar X-Rays; Electron Density (Concentration); Forbidden Transitions; Helium Ions; Line Spectra; Plasma Turbulence; Astrophysics; Electron Densities:Solar Flares; Solar Flares:XUV full text sources ADS |