X-ray pulse emission from cesium chloride aqueous solutions when irradiated by double-pulsed femtosecond laser pulses

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