August 1, 2015.
High resolution crystal spectrometers on sounding rockets and orbiting satellites, such as the Solar Maximum Mission, show strong X-ray emission from the n= 3 to 2 transitions in neon-like Fe XVII. Two of the strongest lines are the 3d to 2p resonance and inter combination lines at 15.01 Å (3C) and 15.26 Å (3D).
Intensity ratios of these solar lines range from ~ 1.6 to 2.8. The lower ratios are a result of a line from Na-like Fe XVI inner shell satellite line blending with the Fe XVII inter combination line, 3D. The wavelength of the Na-like line is not known.
Here we present the results of the first attempt to measure this wavelength using LLNL’s electron beam ion trap EBIT-I together with a vacuum crystal spectrometer. The crystal spectrometer employs a beryl crystal for dispersion.
Instrumentation | The Sun and the Solar System
Lawrence Livermore National Laboratory (LLNL)
This material is based upon work supported by the S.D. Bechtel Jr. Foundation and is made possible with contributions from the National Science Foundation under Grant No. 1340110, Howard Hughes Medical Institute, Chevron Corporation, National Marine Sanctuary Foundation, and from the host research center. Any opinions, findings, and conclusions or recommendations expressed in this material are solely those of the authors. The STAR Program is administered by the Cal Poly Center for Excellence in STEM Education on behalf of the California State University system.