EMR Measurement and EMC Design of Underwater Plasma Sound Source

The underwater plasma sound source, as a significant application of pulsed discharge in water, has been employed for underwater acoustics. During the underwater high-voltage discharge, there will be an intense electromagnetic radiation (EMR). Therefore, it is necessary to decrease the level of EMR. So firstly, the mechanism of the EMR during the underwater high-voltage discharge has been studied deeply. Secondly, in terms of the national standards and electromagnetic interference (EMI) theory, the parameters of antenna were confirmed. Thirdly, by using the antenna and some accessories, the EMR of the system has been measured and its characteristics of the time domain and the frequency domain were analyzed. The results show that EMI is serious. Lastly, in order to reduce the level of EMR, the electromagnetic compatibility (EMC) design was used and some experiments using the modified system have been done. Under some special situations, the level of the EMR was reduced over 6 dB.