Atomic number Z dependence of dynamics of laser-ablated materials

We simulate the density and temperature of laser-produced plasmas for various atomic number Z materials covering from Li to Au. In the range of the intensity from 109 to 1014 W/cm2 of 1 ns and 1.06 μm wavelength Nd:YAG lasers, the ablated plasma is modeled well by the constant temperature expansion model. We carried out radiation hydrodynamic simulations for the density scale length around the electron density of 1023 to 1020 cm−3, to examine its dependence on the atomic number Z. At the laser intensity of 1010 W/cm2, our simulation shows that the Z dependence of the scale length is proportional to Z1/2. For more intense laser, the Z dependence weakens, and the scale length becomes almost independent of Z. We point out that the simulated profiles, such as the density and temperature, and especially the double ablation structure of high Z material, are rather sensitive to use of different radiation opacity models.