EBIT Charge-Exchange Measurements and Astrophysical Applications

The past decade has seen a surge of interest in astrophysical charge exchange (CX). The impetus was the discovery of X-ray emission from comets in 1996, soon followed by the observation of CX emission in planetary atmospheres and throughout the heliosphere. Geocoronal and heliospheric CX are now recognized to contribute a considerable fraction of the soft X-ray background, and stellar-wind charge exchange is expected to occur in the astrospheres surrounding many stars. CX may also contribute to X-ray line emission in supernova remnants, the Galactic Center, and the Galactic Ridge. This article summarizes the key aspects of CX X-ray emission and its astrophysical relevance, and reviews related laboratory measurements and theoretical predictions with particular attention to spectroscopy experiments conducted on electron beam ion traps.