Time resolved corpuscular diagnostics of plasmas produced with high-intensity femtosecond laser pulses

Ion acceleration dynamics from a water microdroplet target driven by intense (about 1019 W cm-2) femtosecond laser pulses has been investigated. A gated Thomson-parabola spectrometer with a temporal resolution of a few hundreds of picoseconds allows one to measure the temporal development of the ion acceleration process for different charge states and energies. It was found, within the resolution of the measurement, that all ion species are accelerated simultaneously in the same built-up electric field. The ion acceleration during a very short time period results in a very broad instantaneous energy (velocity) spread. The measured time-resolved ion spectra are in good agreement with calculated ones. It shows that the ion acceleration created by a highly intense femtosecond laser pulse can be described in the frame of a model, where the acceleration starts simultaneously for all ions. The temporally resolved ion spectra, measured on the basis of the elaborated diagnostics, show great potential for studies of ion acceleration processes in femtosecond laser pulse driven plasmas