Correlation between laser accelerated MeV proton and electron beams using simple fluid model for target normal sheath acceleration

High density energetic electrons that are created by intense laser plasma interactions drive MeV proton acceleration. The correlation between accelerated MeV protons and escaped electrons is experimentally investigated at laser intensities in the range of 1018–1019 W/cm2 with S-polarization. Observed proton maximum energies are linearly proportional to escaped electron slope temperatures with a scaling coefficient of about 10. In the context of the simple analytical fluid model for transverse normal sheath acceleration, hot electron sheath density near the target rear surface can be estimated if an empirical acceleration time is assumed.