Spectroscopic Laboratory Astrophysics Experiments Conducted at the LLNL EBIT Facility in Support of NASA's X-ray Astronomy Flight Program

International audienceThe electron beam ion trap (EBIT) facility located at the Lawrence Livermore National Laboratory has been used for laboratory astrophysics experiments for over 15 years. During this time, several unique spectrometers and operating modes have been developed and implemented, including high resolution grating and crystal spectrometers, a high-resolution, high-efficiency NASA/GSFC microcalorimeter array, and the ability to operate and record datawith the electron beam turned off, i.e., in the so-called magnetic trapping mode. Targeted experiments conducted at this facility have addressed specific problems faced by the X-ray astrophysics community and have provided accurate, complete sets of atomic data such as relative and absolute excitation cross sections, transition wavelengths, line polarization, and X-ray signatures of charge exchange recombination. Here we will present a brief overview of our facility and some of the more recent results including 1/4 keV band X- ray emission produced by charge exchange between L-shell sulfur ions and neutral gas, wavelengths and relative intensities of satellite X- ray lines from Na-like Fe XVI and their contribution to the Fe XVII line emission, and the relative intensities of the 3s-2p/3d-2p lines in F-like Fe XVIII and Ni XX. Part of this work was performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and is also supported by NASA grants to LLNL, GSFC, and Stanford University