We have studied the ion emission in the interaction between femtosecond laser pulses and solid targets by experiments and particle-in-cell(PIC)simulations.We found experimentally that almost all of the fast ions are c...We have studied the ion emission in the interaction between femtosecond laser pulses and solid targets by experiments and particle-in-cell(PIC)simulations.We found experimentally that almost all of the fast ions are confined within a cone symmetrically around the normal direction of targets.The PIC simulation results demonstrate that the fast ion beam can be accelerated by the laser-induced electrostatic field in front of solid targets.展开更多
The effects of laser polarization on super-hot electron (> 100 keV) generation have been studied in the interaction of femtosecond laser light (800 nm, 150 fs, 6 × 10^(15) W·cm^(-2)) with a pre-formed pla...The effects of laser polarization on super-hot electron (> 100 keV) generation have been studied in the interaction of femtosecond laser light (800 nm, 150 fs, 6 × 10^(15) W·cm^(-2)) with a pre-formed plasma from a slab Cu target. For p-polarized laser pulses, high-energy γ-rays of the energy ~400keV were detected. The electron temperatures deduced from the γ-ray spectra were 66 and 52keV, respectively, in normal and reflective directions of the solid target, and hot electrons were emitted out of the plasma mainly in the normal direction. In contrast, there were nearly no γ-rays >100keV found for s-polarized laser pulses. The hot electron temperature was 26keV and the emission of hot electrons was parallel to the laser field. The superposition of resonant field with electrostatic field excited by escaping electrons may contribute to the high-energy γ-ray or super-hot electron (> 100 keV) generation.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.19825110,10005014,and 10075075the National Key Basic Research Special Foundation(NKBRSF)(Grant No.G1999075200).
文摘We have studied the ion emission in the interaction between femtosecond laser pulses and solid targets by experiments and particle-in-cell(PIC)simulations.We found experimentally that almost all of the fast ions are confined within a cone symmetrically around the normal direction of targets.The PIC simulation results demonstrate that the fast ion beam can be accelerated by the laser-induced electrostatic field in front of solid targets.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19854001,10005014 and 19825110the National Hi-Tech ICF Programme。
文摘The effects of laser polarization on super-hot electron (> 100 keV) generation have been studied in the interaction of femtosecond laser light (800 nm, 150 fs, 6 × 10^(15) W·cm^(-2)) with a pre-formed plasma from a slab Cu target. For p-polarized laser pulses, high-energy γ-rays of the energy ~400keV were detected. The electron temperatures deduced from the γ-ray spectra were 66 and 52keV, respectively, in normal and reflective directions of the solid target, and hot electrons were emitted out of the plasma mainly in the normal direction. In contrast, there were nearly no γ-rays >100keV found for s-polarized laser pulses. The hot electron temperature was 26keV and the emission of hot electrons was parallel to the laser field. The superposition of resonant field with electrostatic field excited by escaping electrons may contribute to the high-energy γ-ray or super-hot electron (> 100 keV) generation.
