Impact of FBG array embedded on/in helix support rods on TWT performance

In order to obtain the temperature distribution along inner helix of working TWTs, fiber Bragg grating array (FBGA) can be considered to be used in testing the temperature. Two testing methods based on FBGA embedded on/in support rod helix structure are proposed. The influence of the FBGA on beam-wave interaction is analyzed through CST. The results show that the structure with FBGA embedded in support rods doesn't significantly reduce the saturated output power and can suppress the backward wave oscillation (BWO) power hole.