Presentation #103.64 in the session Missions and Instruments.
The scientific return from the Chandra and XMM-Newton X-ray grating spectrometers, followed by a multitude of results from Hitomi's quantum calorimeter, have solidified the power of high-resolution X-ray spectroscopy for diagnosing astrophysical sources. The high spectral resolution, high signal-to-noise X-ray spectra provided by these instruments have not only helped unravel the physics of celestial sources, but have driven the laboratory astrophysics community to produce higher accuracy results. The resulting interplay between atomic theory and experiment has produced new levels of accuracy and completeness. With the launch of the Resolve calorimeter spectrometer on the X-ray Imaging and Spectroscopy Mission (XRISM), the next decade will surely see this synergy play out again. One of the processes that, in many cases, requires more attention before reaching the standard of accuracy Resolve demands, is dielectronic recombination (DR). The resonant nature of the recombination process means DR can significantly affect a plasma’s charge balance and can be used as a highly sensitive temperature diagnostic. DR plays a significant role not only in sources that are in near equilibrium, such as galaxy clusters, but also transient sources, such as supernova remnants. Emission from relatively weak DR channels may also play a role in the excess reported at 3.5 keV. Multiple terrestrial-based laboratory measurements of DR emission in the X-ray band have been completed using electron beam ion traps (EBITs), magnetic fusion devices, and high power lasers. In the interest of reducing the uncertainty of DR to better suit Resolve, new measurements of DR emission, including emission from all radiative decay paths, are being conducted at Lawrence Livermore National Laboratory’s EBIT facility. Recent results from LLNL’s EBIT-I and comparisons to results from other facilities and standard spectral models will be presented. Prepared by LLNL under Contract DE-AC52-07NA27344 and supported by NASA grants to LLNL, NASA/GSFC, and Center for Astrophysics | Harvard & Smithsonian