Laboratory Astrophysics, Electron Beam Ion Traps, and the Fe XVII Saga

Program Description

High resolution, high throughput soft x-ray spectroscopy of celestial sources has been largely enabled by instruments on the Chandra and XMM-Newton X-ray Observatories, and in early 2016, it will be extended to the Fe K band by the launch of the calorimeter spectrometer on the Astro-H X-ray Observatory. The diagnostic utility of the these spectrometers is directly coupled to, and often limited by, our understanding of the x-ray production mechanisms associated with the highly charged ions present in the source. One of the more vexing, long standing problems facing the x-ray astrophysics community involves the neon-like Fe XVII x-ray spectrum, i.e., disagreement among different theoretical models and models and observations have limited its diagnostic utility. To address this problem, we have used the LLNL EBIT-I electron beam ion trap, and more recently, MPIK's portable FLASH-EBIT coupled to third and fourth generation advanced light sources, to study the Fe XVII spectrum in well controlled laboratory environments. The results of this work will be presented.