A 10 fs X-ray emission switch driven by an intense X-ray free electron laser

Abstract We propose an intrinsic fast X-ray switch driven by the radiation emission from hollow ion states K 0 L n . The switch is designed primarily for the investigation of the transient evolution of X-ray emission from high density plasmas created by short pulses ( 0.5 ps) and the X-ray emission from the low density regime can only be suppressed with a fast switch approach. Simulations carried out for short pulse (100 fs) intense X-ray free electron laser radiation (XFEL) interacting with dense plasmas demonstrate that the hollow ion X-ray emission switch has a time scale faster than 50 fs. This time window enables the probing of plasmas of the highest density even if time integrated spectroscopic techniques are employed.