X-ray and fast ion generation has been studied by femtosecond laser irradiation (52fs, 790nm) on metal targets (copper and iron), where hard X-ray emission takes place at power density up to 1017W/cm2. X-ray intensities and kinetic energy distributions of ions are observed as a function of the power density. The ion energy distributions for each target show several peak components, which are fast ions (high-energy component in keV range), and additional low-energy component (a few hundreds of eV). Average fast ion energies show a strong dependence on the power density, and are comparable to ponderomotive potential. © 2002 Elsevier Science B.V. All rights rererved.
Okano, Y., Kishimura, H., Hironaka, Y., Nakamura, K. G., & Kondo, K. I. (2002). X-ray and fast ion generation from metal targets by femtosecond laser irradiation. In Applied Surface Science (Vol. 197–198, pp. 281–284). https://doi.org/10.1016/S0169-4332(02)00383-5