Investigation of effects of double pulse configuration on efficiency of Ni-like and Co-like X-ray resonance lines emitted from laser produced silver plasmas

Abstract

Ni-like and Co-like X-ray resonance line spectra are simulated between 16 A and 32 A emitted from silver plasma using Nd:YAG laser and its second, third and fourth harmonics for double pulse configurations. In addition to spectral lines, X-ray intensities obtained from free-bound and free-free continuum emission from Zn-, Cu-, Ni-, Co-and Fe-like ions are calculated between 1 A and 30 A. The intensity for 280 ps pre-pulse is 5.4 × 1012 W/cm2 and for 1.2 ps short pulse is 4.4 × 1015 W/cm2. The time difference between pre-pulse and short pulse is varied between 150 ps and 750 ps. X-ray energy conversion efficiencies and X-ray pulse durations are calculated from X-ray spectra. For example, maximum X-ray energy conversion efficiency for 750 ps time difference is obtained as 0.54 % for fundamental harmonic Nd:YAG laser, 1.01 % for second harmonic, 1.46 % for third harmonic, 1.86 % for fourth harmonic over 2π sr. The ratio of Co-like 3d → 4f and Ni-like 3d → 4f resonance line intensities is calculated to determine electron temperature.