Straight plasma channels are widely used to guide relativistic intense laser pulses over several Rayleigh lengths for laser wakefield acceleration. Recently, a curved plasma channel with gradually varied curvature was suggested to guide a fresh intense laser pulse and merge it into a straight channel for staged wakefield acceleration [Phys. Rev. Lett. 120, 154801 (2018)]. In this work, we report the generation of such a curved plasma channel from a discharged capillary. Both longitudinal and transverse density distributions of the plasma inside the channel were diagnosed by analyzing the discharging spectroscopy. Effects of the gas-filling mode, back pressure and discharging voltage on the plasma density distribution inside the specially designed capillary are studied. Experiments show that a longitudinally uniform and transversely parabolic plasma channel with a maximum channel depth of 47.5 μm and length of 3 cm can be produced, which is temporally stable enough for laser guiding. Using such a plasma channel, a laser pulse with duration of 30 fs has been successfully guided along the channel with the propagation direction bent by 10.4°.

以能量平衡方程为基础，采用不同的电导率唯象模型描述了液相放电等离子体圆柱形通道特性，得到了通道内半径、温度、电阻、电流和耗散能量随时间的变化关系，还给出了距离放电间隙中心一定距离处的冲击波压力变化，并与前人利用等离子体通道球状模型计算得到的结果进行了比较。结果表明：把等离子体通道看成球状和看成圆柱状在描述通道压力和通道半径时差异显著，而在描述其他物理特性时差别不大；三种电导率模型在描述等离子体通道物理特性时，变化趋势大体相同，而在描述激波特性时，电导率模型σ₂更符合实际；通过对比电学参数与压力参数的变化，就可以在实验中根据实验数据以及具体的研究问题进行模型的适用性选择。

基于相应的数学模型来表征液电脉冲激波的产生和传播过程，搭建了液电式碎岩综合试验平台，分析了典型的激波特性的仿真和实测结果。给出了不同充电电压下液电脉冲激波特性的仿真结果，并分析了充电电压对激波特性的影响。结果表明：充电电压为11 kV时，激波的压力峰值为2.67 MPa，激波能量为27.30 J，波前时间为2.16 μs，激波加载速率为1.24 MPa/μs，电能转化为激波能量的效率为13.35%；提高电容充电电压，激波压力峰值和激波能量增大，波前时间减少，激波加载速率增加，但电能转化为激波能量的效率降低。利用建模分析的方法，可以根据放电回路参数预测液电脉冲激波特性，从而为进一步研究激波破碎岩石的形态和效果提供理论依据。