Electromagnetic pulse characteristic in process of laser shooting

To capture the electromagnetic pulse (EMP) generated by the interaction between laser and target, a loop antenna (B-dot) is chosen as the main EMP signal acquisition device. The signals inside and outside the target chamber are tested simultaneously. This paper focuses on the design and fabrication of antenna and antenna calibration. An EMP diagnostic system is established. The EMP characteristics are investigated by comparing the pulse signals. It turns out that the EMP possessed maximum strength inside the target chamber, followed by the signal on the flange, and it is weakest outside the chamber. Summarizing the multiple EMP frequency spectra, we figure out the crests mainly exist at 0.5, 1.2, 3 GHz. Time-domain EMP distributions regularly demonstrate the pulse lasts about 100 ns. In addition, the EMP signal presents obvious peak clusters at several ns and dozens of ns respectively due to the back oscillation inside the target chamber.