The interaction between time-tailored, high-intensity laser radiation and spherical light-element targets is investigated. Simultaneous measurements of the laser plasma electron temperature, charged-particle distribution, absorbed energy, neutron yields and backscattered light intensity and spectra were made. For 100 ps, wide laser pulses focused to intensities ranging between 3 × 1015 and 2 × 1016 W/cm2 on 150-200μm-diameter LiD and C36D74 targets, plasmas with electron temperatures up to 1.2 keV and target-generated yields of up to 4 × 104 neutrons are produced. The absorption can be accounted for by inverse bremsstrahlung and no.significant contributions due to parametric instabilities are observed. No more than 10−1 of the incident laser energy is back-reflected into spectral components at ωL, (3/2,)ωL, and 2ωL.
Focus optimization of relativistic self-focusing for anomalous laser penetration into overdense plasmas (super-penetration)