Actions for Deriving Plasma Densities and Elemental Abundances from SERTS Differential Emission Measure Analysis

Email RIS file
Bookmark
Report an Issue

Deriving Plasma Densities and Elemental Abundances from SERTS Differential Emission Measure Analysis

Author
Schmelz, J. T.
Published
September 20, 2012.
Physical Description
1 electronic document
Additional Creators
Kimble, J. A. and Saba, J. L. R.
Online Version

Availability

I Want It
I Want It

Finding items...

Restrictions on Access
Unclassified, Unlimited, Publicly available.
Free-to-read Unrestricted online access
Summary
We use high-resolution spectral emission line data obtained by the SERTS instrument during three rocket flights to demonstrate a new approach for constraining electron densities of solar active region plasma.We apply differential emission measure (DEM) forward-fitting techniques to characterize the multithermal solar plasma producing the observed EUV spectra, with constraints on the high-temperature plasma from the Yohkoh Soft X-ray Telescope. In this iterative process, we compare line intensities predicted by an input source distribution to observed line intensities for multiple iron ion species, and search a broad range of densities to optimize chi-square simultaneously for the many available density-sensitive lines. This produces a density weighted by the DEM, which appears to be useful for characterizing the bulk of the emitting plasma over a significant range of temperature. This "DEM-weighted density" technique is complementary to the use of density-sensitive line ratios and less affected by uncertainties in atomic data and ionization fraction for any specific line. Once the DEM shape and the DEM-weighted density have been established from the iron lines, the relative elemental abundances can be determined for other lines in the spectrum. We have also identified spectral lines in the SERTS wavelength range that may be problematic
Other Subject(s)
Collection
NASA Technical Reports Server (NTRS) Collection.
Note
Document ID: 20140006618.
GSFC-E-DAA-TN9415.
The Astrophysical Journal; Volume 757; No. 1; 17.
Terms of Use and Reproduction
Copyright, Distribution under U.S. Government purpose rights.
View MARC record | catkey: 15437240