强激光靶耦合产生电磁脉冲信号处理方法研究

Study the Methods of Processing Electromagnetic Pulses Generated by the Intense Laser Interacting Solid Targets

基于惯性约束聚变的激光靶耦合过程会产生大量的电磁脉冲,严重影响诊断设备的正常运行和测试数据的精确采集。该文采用Tikhonov正则化结合L-curve参数优化法,通过把电场、电压和传递函数的关系离散化,绘制L曲线图以确定最适正则化参数,从而对测试数据进行优化。结果表明,L-curve在成功消除病态数的同时还具有较强的抗噪声抗干扰性能,达到明显数据优化作用。

Massive electromagnetic pulses can be generated by the interactions between intensive laser and solid targets in inertial confinement fusion （ICF）, which will lead to malfunction of the diagnostic setups and inaccuracy of experimental data. In order to deeply grasp the physical mechanism of electromagnetic pulses and make well preparations for further electromagnetic shielding, it is significant to correctly collect and treat the pulse signals. Due to various interferences, the captured voltage signal is distortion, which needs to be properly treated. The transfer function, derived by deduction and simulation, is deemed as a bridge to interconnect the voltage signal and electric field. Nevertheless, an ill-posed issue in low frequency ranges will be aroused when using the transfer function to obtain electric field. Therefore, we use a Tikhonov regularization method with an L-curve parameter optimization to eliminate the ill-posed issue that is expected to bring about massive noise. To achieve the final electric field, the L-curve diagram is created to optimize the related parameters. The results indicate the L-curve technique can not only resolve the ill-posed problem, but it can also enhance the anti-interference ability.