In this work we present experiments by focusing 42 femtosecond laser pulses in air using three differentfocal length lenses: f=100, 30 and 5 cm. For the longest focal length, only the filament, which is aweak plasma c...In this work we present experiments by focusing 42 femtosecond laser pulses in air using three differentfocal length lenses: f=100, 30 and 5 cm. For the longest focal length, only the filament, which is aweak plasma column,is observed. When the shorter focal length lens is used, a high density plasma isgenerated near the geometrical focus and coexists with a weak plasma channel of the filamemt. Under thetightest focusing condition, filamentation is prevented and only a strong plasma volume appears at tehgeometrical focus.展开更多
An experiment was performed on the Shenguang III prototype laser facility to continue the study on hohlraum radiation source with approximately constant radiation temperature using a continuously shaped laser pulse.A ...An experiment was performed on the Shenguang III prototype laser facility to continue the study on hohlraum radiation source with approximately constant radiation temperature using a continuously shaped laser pulse.A radiation source with a flattop temperature of about130 e V that lasted about 5 ns was obtained.The previous analytical iteration method based on power balance and self-similar solution of ablation was modified taking into account the plasma movements and it was used to design the laser pulse shape for experiment.A comparison between experimental results and simulation is presented and better agreement was achieved using the modified method.Further improvements are discussed.展开更多
文摘In this work we present experiments by focusing 42 femtosecond laser pulses in air using three differentfocal length lenses: f=100, 30 and 5 cm. For the longest focal length, only the filament, which is aweak plasma column,is observed. When the shorter focal length lens is used, a high density plasma isgenerated near the geometrical focus and coexists with a weak plasma channel of the filamemt. Under thetightest focusing condition, filamentation is prevented and only a strong plasma volume appears at tehgeometrical focus.
文摘An experiment was performed on the Shenguang III prototype laser facility to continue the study on hohlraum radiation source with approximately constant radiation temperature using a continuously shaped laser pulse.A radiation source with a flattop temperature of about130 e V that lasted about 5 ns was obtained.The previous analytical iteration method based on power balance and self-similar solution of ablation was modified taking into account the plasma movements and it was used to design the laser pulse shape for experiment.A comparison between experimental results and simulation is presented and better agreement was achieved using the modified method.Further improvements are discussed.
