[Study of soft X-ray radiation in 8-20 nm region from a laser plasma source]

A repetitive-laser-produced-plasma (LPP) soft X-ray source with a pulse repetition rate up to 10 Hz was developed. Spectra ranging from 8 to 20 nm were obtained from plasmas generated respectively by a 100 mJ (lambda = 0.53 microm) and 800 mJ (lambda = 1.06 microm) Nd:YAG laser focused on the following different target materials: C, Mg, Al, Ti, Fe, Cu, Zn, Sn, W, Pb and Bi. The dependence of spectral distribution on the target materials and laser parameters, such as pulsed laser energy, laser focus power density etc. are analyzed. The intensities of the soft X-ray radiation with different atomic numbers are characterized.