By using the method

employing the variation in resistance of helix with temperature

the heat dissipation capability of the helix traveling-wave tube slow-wave structure(SWS) made by several helix assembling methods have been tested.The results of this study have demonstrated that four assembling methods

i.e.

the graphite wrapping method

the hot insertion method

the sputtering brazing method and the diffusion brazing method have better heat dissipation capability of the SWS than that of the cold compress method and the molybdenum wrapping method .The SWS made by hot insertion method has a smaller microwave reflecting than that of the graphite wrapping method.The diffusion brazing SWS have a little better heat dissipation capability and lower microwave losses than that of the sputtering brazing SWS.These results can lead to improved helix TWT designs and performance.