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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 rhenium-doped tungsten-based alloy cathode was studied and the doping ratio of rhenium was optimized. It was found that when the weight percentage of rhenium doping is 5wt%, the cathode of the rhenium alloy possesses the maximum secondary electron emission coefficient of 1.8, Compared to pure tungsten sintered cathode can increase 80%. The thermal emission of a 5wt% rhenium-doped tungsten-based alloy cathode was studied. It was found that the cathode not only retained the good emission stability of the pure W filament cathode, but also possessed the advantages of good electron emission resistance, ion bombardment ability and anti-poisoning ability. But also has a larger thermal emission current density. Experimental results show that the new type of alloy cathode can provide at least 400 ℃ lower temperature than pure W filament cathodes while providing the same thermal emission current density as pure W filament cathodes. The theoretical calculation shows that the work function of this alloy cathode is only 3.6, which is 20% lower than that of pure W filament cathode obtained under the same conditions. Lifetime experiments show that the cathode of the alloy has been operating normally for more than 2000 hours at a temperature of 1800 ° C in a vacuum diode and that no evapotranspiration has been detected.