Optimization of 4.7-keV X-ray titanium sources driven by 100-ps laser pulses

摘要

An experiment with thin titanium foils irradiated by two pulses delayed in time is conducted on the Shenguang-Ⅱ laser facility.A prepulse induces an underdense plasma,2-ns later a main pulse (λL =0.35 μm,EL ≈ 120 J,τL ≈ 100 ps) is injected into the underdense plasma and produces strong line emission from the titanium K shell (i.e.,Heα at 4.7 keV).Data show that the intensity of 4.7-keV X-ray emission with the prepulse is approximately twice more than without the prepulse,and can be used as a backlighting source satisfying the diagnostic requirements for dense plasma probing.Highquality plasma images are obtained with the backlighting 4.7-keV X-rays in a Rayleigh-Taylor hydrodynamic instability experiment.