X-ray spectroscopic study on femto- and pico-second laser irradiated solid and gaseous targets

The soft x-ray emission from He-like and H-like were obtained by using the double nozzle gas-puff (Nitrogen, and Oxygen) target irradiated by the laser which delivered a laser energy of 50 mJ in 400 ps pulse width. Efficient absorption of the incident laser energy into the double gas-puff target was demonstrated experimentally such as 15%, and 29% for Nitrogen and Oxygen, respectively. The sub keV x-ray emission from He-β(1s2-1s2p, 1s2-1s3p, and 1s2-1s4p) lines are observed around the 0.4 nm wavelength region by using the double nozzle Argon gas-puff target irradiated by a 5 J, 1 ns, 1 μm laser. Using the gas-puff target irradiated by a femto-second laser pulse, highly ionized ions of Cr-, Fe- and Ni-like Kr at the 5 - 20 nm wavelength region have been observed in a laser produced plasma. However, the intensity of the x-ray emissions from double nozzle gas-puff target are lower than that from the single nozzle gas-puff targets, using the Krypton gas. Using xenon gas, the intensity of the x-ray emissions from double nozzle gas-puff target is equivalent to that from the single nozzle target.