Influence of target geometry on the ion temperature of laser-produced plasmas

Thomson scattering measurements of laser-produced plasmas have been performed with a 4ω probe beam in Shenguang II laser facility. Three kinds of the targets are irradiated with 3ω laser beams: disc target, curved target, and void hohlraum. Thomson scattering spectra are quite different with the different targets. The two ion-acoustic resonance peaks become much broader when a curved target or a hohlraum is irradiated. The experimental results show that the target geometry has a strong influence on the ion temperature of the laser-produced plasmas. The ion temperature could be about several ten keV in the plasma produced with curved target or hohlraum