X-ray generation from laser-produced plasmas and its atomic-number dependence

Experimental studies of the x-ray generation from laser plasmas are performed by using a picosecond high-power laser. The intensity of emitted x rays shows a periodic variation as a function of the atomic number of target materials. Calculations based on the transient collisional-radiative model, rather than the conventional steady-state coronal model, are carried out. Experimental and computational results show good agreement with each other, and indicate the importance of the transient nature of multiple-ionization processes. The dependence of hot-electron temperature on the atomic number is briefly discussed.