一种进行激光等离子体通道实验的设计

An Experimental Design of the Laser Plasma Channeling

利用一束激光产生等离子体通道,进而使点火激光能顺利到达高密度区是快点火理论中实现点火的一个重要过程。提出了一种利用神光Ⅱ的二路装置产生通道的设计。该设计将其中一路长脉冲激光(350 ps,1.053μm)辐照靶箔产生等离子体,用另一路短脉冲激光(1 ps,1.053μm)在上述预等离子体中打通道,并将后者的一部分激光经分离和四倍频(0.263μm)后作探针光,采用Normaski型偏振干涉系统对通道等离子体电子密度分布进行干涉诊断测量的实验研究设计。

It is important in fast ignition （FI） to drill a channel in the coronal plasma by a long intense pulse firstly, since we expect the following ultra-intense pulse will reach more easily the dense core to obtain the fuel burning. An experimental design to study the plasma channeling was presented at two beams laser sub-picosecond （SPS） Facility of National Laboratory of High Power Laser and Physics. One beam with 1. 053 μm and 350 ps full width at half maximum （FWHM） was used to form the pre-plasma. And then, a most part of another one with the same wavelength and 1 ps FWHM was focused on the plasma for channeling. The rest part of the 1 ps laser beam, frequency quadrupled to λ =0. 263μm, was as a probe used in Normaski polarization interferometry to diagnosis the electron density distribution of the channel.