Laboratory simulation of cometary x rays using a high-resolution   microcalorimeter
  X-ray emission following charge exchange has been studied on the University of California Lawrence Livermore National Laboratory electron beam ion traps EBIT-I and EBIT-II using a high-resolution microcalorimeter. The measured spectra include the K-shell emission from hydrogenlike and heliumlike C, N, O, and Ne needed for simulations of cometary x-ray emission. A comparison of the spectra produced in the interaction of O8+ with N2 and CH4 is presented that illustrates the dependence of the observed spectrum on the interaction gas. 
P. Beiersdorfer, H. Chen, K. R. Boyce, G. V. Brown, R. L. Kelley, C.   A. Kilbourne, F. S. Porter, S. M. Kahn