Silicon Abundance from RESIK Solar Flare Observations

摘要: The RESIK instrument on the CORONAS-F spacecraft obtained solar flare and active-region X-ray spectra in four channels covering wavelength range 3.8 – 6.1 A its operational period between 2001 2003. Several highly ionized silicon lines were observed within of long-wavelength channel (5.00 – 6.05 A). fluxes Si xiv Ly-β line (5.217 A) Si xiii 1s 2 – 1s3p (5.688 A) during 21 flares with optimized pulse-height analyzer settings have been analyzed to obtain abundance relative hydrogen plasmas. As previous work, emitting plasma for each spectrum is assumed be characterized by a single temperature emission measure given ratio two GOES. determined A(Si)=7.93±.21 (Si xiv) 7.89±.13 (Si xiii) logarithmic scale H=12. These values, which vary only very small amounts from times flares, are 2.6±1.3 2.4±0.7 photospheric abundance, about factor three higher than measurements low activity. There suggestion that Si/S increases active regions flares.