The intensity of x-ray emission from the aqueous solutions irradiated with focused femtosecond laser pulses (main pulses and relatively low-intensity prepulses) was measured as a function of the delay time between the main pulses and prepulses. Four different x-ray intensity peaks were observed in the picosecond and nanosecond ranges. The prepulse irradiation caused an increase in the x-ray intensity by a factor of 103 - 104, as confirmed by x-ray emission spectroscopy. Time-resolved reflectance measurements and imaging revealed that the increase was caused by the solution surface dynamics such as the picosecond plasma formation and decay and the transient (nanoseconds) surface roughness.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)