Error effect of 3 dB coupler on energy doubler performance

According to the SLED (SLAC energy doubler) working principle, the error effect of the 3 dB coupler on the SLED performance has been studied theoretically. In the meantime, the effect of the 3 dB coupler on the SLED used in the BEPC and BEPC Ⅱ linac is investigated. These analyses provide theoretical reference for judging the waveguide distortion of the 3 dB directional coupler after final assembly and welding. Both power imbalance error and phase difference deviation will cause reflection of the RF power back to the klystron. The larger the power imbalance error and the phase difference deviation are, the more the power multiplication factor decreases. (authors)