Improved data for solar flare X-ray spectral analysis

¹ National Research Council Senior Research Associate, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
² Space Science and Technology Dept., Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK
³ Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
⁴ Observatoire de Paris–Meudon, Place Jules Janssen, 92195 Meudon, France
⁵ EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK

Corresponding author: K. J. H. Phillips, phillips@stars.gsfc.nasa.gov

Received: 12 September 2003
Accepted: 10 November 2003

Abstract

The inclusion of collisional rates for He-like Fe and Ca ions is discussed with reference to the analysis of solar flare  and  line emission, particularly from the Yohkoh Bragg Crystal Spectrometer (BCS). The new data are a slight improvement on calculations presently used in the BCS analysis software in that the discrepancy in the  y and z line intensities (observed larger than predicted) is reduced. Values of electron temperature from satellite-to-resonance line ratios are slightly reduced (by up to 1 MK) for a given observed ratio. The new atomic data will be incorporated in the Yohkoh BCS databases. The data should also be of interest for the analysis of high-resolution, non-solar spectra expected from the Constellation-X and Astro-E space missions. A comparison is made of a tokamak  spectrum with a synthetic spectrum using atomic data in the existing software and the agreement is found to be good, so validating these data for particularly high-n satellite wavelengths close to the  resonance line. An error in a data file used for analyzing BCS  spectra is corrected, so permitting analysis of these spectra.