Temperature and density measurement of an ultra short laser pulse driven carbon plasma by skin-layer ion emission analysis

This study investigates the plasma properties induced by sub-10-fs laser pulses on carbon bulk targets in the sub 1018W/cm2 regime. Utilizing a Thomson parabola spectrometer, the keV ion emission resulting from skin-layer acceleration is measured. The retrieved spectra are evaluated using the Saha equations to deduce the transient plasma temperature and density in early states of the plasma. The results of the Saha solver, in agreement with experimental data, affirm the validity of a local thermodynamic equilibrium. Thereby, the temporal and spatially localized nature of the ion ejection mechanism is leveraged to obtain a snapshot of those parameters. In addition, a comparative analysis of carbon ion emissions and residual hydrogen ions offers insights into the plasma dynamics and possible future applications.