The calculation of leaked electromagnetic field in gallery of klystron of NSRL

The HF microwave leak in the gallery of klystron of NSRL affects microwave communication greatly. In order to reduce electromagnetic radiation noise, it is necessary to locate the noise source. But for the complicated leaked field, it is difficult to locate the noise source. We can test field and calculate it, so as to locate the radiation noise source and study the method of reduction of the electromagnetic noise. This article gives the method and formulae of calculation of electromagnetic field, and also contrast test.