Isochoric heating of reduced-mass targets in short pulse laser experiments at 0.53 $\mu $m

Recent works have shown the possibility to heat isochorically mass limited targets by using the electron refluxing. We report on experiment performed at the 100 TW LULI laser facility dedicated to the study of fast electron transport in multilayer reduced mass targets. The targets were composed of 0.2V/5Cu/5Al $\mu $m and varied from 300 to 50 $\mu $m in diameter. They were irradiated by a 300 ps laser pulse at 1.057 $\mu $m and 0.53 $\mu $m that delivered I$\sim $2x10$^{19 }$W/cm$^{2}$ and I$\sim $10$^{19 }$W/cm$^{2}$ respectively to form a warm dense plasma. Emission from the rear side was observed using K-alpha spectroscopy and imaging diagnostics. Spectra including the Al and Cu-K-alpha, and Al He-like emissions show changes as a function of total mass. The data obtained from all diagnostics (K-alpha spectroscopy and imagers on the rear side and the transverse side) show a different behavior depending on the incident wavelength.