X-ray pulses were generated by focusing femtosecond infrared laser pulses (775 nm, 130 fs, 0.58 mJ/pulse) onto an alkali metal (Cs or Rb) chloride aqueous solution jet. The mechanism of x-ray pulse generation was studied by measuring x-ray emission spectra and transmitted laser pulse spectra. Addition of CsCl to distilled water was found to enhance markedly x-ray intensity and x-ray cutoff energy. The frequency-up-shift observed in transmitted laser pulses was larger in CsCl solution than in distilled water. The results suggested that a high-density plasma-like medium was produced in CsCl solution due to secondary electrons.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)