Abstract
Transient hollow ion atomic radiation field kinetics is developed which shows that short pulse intense narrow-band X-ray sources enable the rise of hollow ion population densities in dense plasmas more than 10 orders of magnitude higher than without pump. The subsequent hollow ion X-ray emission, which will escape even extremely high-density plasmas without detrimental absorption, will open up a new field of research and allow novel studies of atomic systems in intense Coulomb fields. Simulations including relaxation effects show that for parameters of currently established free-electron X-ray lasers atomic chain reactions can be initiated which drive efficient hollow ion X-ray emission.