Preheating Energy in a Soft-X-Ray-Accelerated Foil

Abstract
Preheated temperature in a soft X-ray driven ablation was found by a double foil experiment to be Tph=2∼12 eV for a 1.7 µm thick Al target at the incident X-ray irradiance of I x=1013 W/cm2. This preheating was caused by the higher hν component (∼1 keV) of the soft X-ray spectrum. Its energy flux was also estimated to be 27∼260 J/cm2.