一种连续波磁控管用铼掺杂钨基合金阴极研究

A Re Doping W Base Alloy Cathode Applied in Continuous Wave Magnetron Tubes

研究了一种铼掺杂钨基合金阴极,并对铼掺杂比例进行了优化,发现铼掺杂重量百分比为5wt%时,该合金阴极拥有最大的二次电子发射系数,其值为1.8,相比于纯钨粉烧结阴极能够提高80%。对5wt%铼掺杂钨基合金阴极的热发射进行了研究,发现该新型合金阴极不仅保留了纯W丝阴极具有发射稳定性好,耐电子、离子轰击能力强,抗中毒性能强等优点,而且还具有较大的热发射电流密度。实验研究表明,该新型合金阴极在提供与纯W丝阴极相同热发射电流密度的同时,能够比纯W丝阴极工作温度低至少400℃以上。理论计算表明该合金阴极的逸出功仅为3.6,比相同条件下获得的纯W丝阴极逸出功低20%。寿命实验显示该合金阴极在真空二极管中1800℃温度下正常工作已经超过2000小时,并且没有监测到蒸散现象。

A Re doping W base alloy cathode is researched.Different Re doping ratio is optimized which shows that W-5 wt%Re cathode has the maximum secondary electron emission coefficient(δm),which is 1.8,and 80% higher than the pure W powder sintering cathode.In addition,the thermionic emission of the W-5 wt%Re cathode is measured,which shows that this novel alloy cathode not only keeps good emission stability,resistive electron and ion bombing,anti-poisoning et al compared with pure W cathode,but also has high thermionic emission current density.Experimental research results show that the W-5 wt%Re cathode can operate at least 400℃ lower than pure W filament cathode under the same thermionic emission current density.Theory calculations show that the effect work function of the cathode is 3.6,which is 20% lower than pure W filament cathode made in the same condition.Lifetime experiment results show that the lifetime of the W-5 wt%Re cathode is above 2000 hours under 1800℃ with no monitoring evaporation.