载人航天用超小型脉冲行波管阴极的研究

Cathode in Minitype Pulse TWT for Carry-Man Spaceflight

为了满足载人航天用超小型脉冲栅控行波管阴极工作温度低、发射电流密度大、阴极活性好及可靠性高等技术要求,本文研制了一种具有NiReIr混合海绵及新型Ti粉激活剂贮存活性物质的新型贮存式氧化物阴极,测试了该阴极的发射性能。结果表明,新型阴极具有良好的发射性能在该行波管中应用脉冲宽度8～10μs,工作比1%,发射电流密度5～6A/cm2,寿命1000h;此外,为了缩短该阴极的启动时间对阴极结构及支撑带材料进行改进,改进后阴极加热功率3.6W在二极管试验中30s启动,成功用于某侦查卫星中。

In order to adapt the technical requirement of the cathode for the minitype pulse TWT used in carry-man spaceflight for low operation temperature,large emission current,good cathode activity and high reliability,a new type of reservoir oxide cathode is discussed in this paper,which includes the development of a Ni-Re-Ir sponge diffusion layer on the Ni net surface and a new Ti powder reservoir emission material.The results show that the new cathode have good emission performance which used in minitype pulse TWT providing 5～6A/cm2 emission current with 8～10μs pulse width and 1% duty cycle at 800℃ and 1000h lifetime.Furthermore,the cathode turn-on time is reduced to 30 second with 3.6 W heating power by improved the cathode structure and the knighthead material.And the improved cathode has successfully been used in some spy satellite TWT.