The X-ray emission from hollow atoms produced by collisions
of multiply charged ions accelerated by a short pulse laser
with a solid or foil is studied theoretically. The possibility
of obtaining a high conversion efficiency X-ray source in an
ultrafast atomic process (∼1 fs) is demonstrated using the
multistep-capture-and-loss (MSCL) model. Such an X-ray source
has a clear advantage for the spectral range around a few
kiloelectron volts over the conventional Kα
X-ray source. Namely, the number of X-ray photons increases as the
laser energy becomes larger and could reach 3 × 1011
photons for a laser energy of about 10 J.
X-ray emission cross sections following charge exchange by multiply charged ions of astrophysical interest