含稀土氧化物难熔盐浸渍W基直热式阴极研究  

Rare Earth Oxide Refractory Metal Salt Impregnated W Based Directly-Heated Cathode

作　　者：漆世锴[1,2] 王小霞[1] 罗积润[1] 胡明炜 李云[1] 

机构地区：[1]中国科学院电子学研究所,高功率微波源与技术重点实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《无机材料学报》2016年第9期987-991,共5页Journal of Inorganic Materials

基　　金：国家重点基础研究发展计划(2013CB328901);国家自然科学基金(11305177)~~

摘　　要：为了提高磁控管阴极的工作性能,采用新型La_2O_3/Y_2O_3-Gd_2O_3-ZrO_2难熔盐浸渍W基制备直热式阴极,并对该阴极的热发射特性和寿命特性等进行了测试。热发射测试结果表明,La_2O_3-Gd_2O_3-ZrO_2浸渍阴极在1600℃可提供超过0.18 A/cm^2的空间电荷限制区电流密度。在同等发射电流下,该浸渍阴极的工作温度比纯W阴极降低至少300℃,该阴极在1750℃,0.5 A/cm^2直流负载下,可以连续工作2100 h。当以Y_2O_3代替La_2O_3,采用相同的配比制备阴极时,1400℃、1700℃下即可分别提供超过0.6、3.4 A/cm^2的空间电荷限制区电流密度。Y_2O_3-Gd_2O_3-ZrO_2浸渍阴极的工作温度比La_2O_3-Gd_2O_3-ZrO_2浸渍阴极降低至少400℃,该阴极在1600℃,1.5 A/cm^2直流负载下,可以连续工作2600 h。最后,对这两种新型含稀土氧化物难熔盐浸渍阴极的热发射机理进行了探讨。Cathode plays an important role in the magnetron. In order to enhance the emission current, reduce the Ol0_ eration temperature and prolong the lifetime of the pure W cathode applied in the magnetron, a new La2O3/Y2O3-Gd2O3-ZrO2 impregnated W based directly-heated cathode was developed. The thermionic emission properties of the La2O3/Y2O3-Gd2O3-ZrO2 impregnated cathode were measured. The results show that the La2O3-Gd2O3-ZrO2 impregnated cathode can provide more than 0.18 A/cm^2 current density for the space charge limitation （SCL） at 1600℃. Under the same thermionie emission level, the working temperature of the La2O3-Gd2O3-ZrO2 impregnated cathode is at least 300℃ lower than that of the pure W cathode. Lifetime of the La2O3-Gd2O3-ZrO2 impregnated cathode reaches 2100 h at 1750℃ with dc load of 0.5 A/cm^2. The Y2O3-Gd2O3-ZrO2 impregnated cathode can provide more than 0.6 and 3.4 A/cm^2 current density for SCL at 1400℃, 1700℃, respectively. Under the same thermionic emission level, the working temperature of the Y2O3-Gd2O3-ZrO2 impregnated cathode is at least 400℃, lower than that of the La2O3-GdzO3-ZrO2 impregnated cathode. Lifetime of the Y2O3-Gd2O3-ZrO2 impregnated cathode reaches 2600 h at 1600℃ with dc load of 1.5 A/cm^2. At last, the thermionic emission mechanisms of the two new im- pregnated cathodes are discussed reasonably.

关 键 词：直热式阴极 稀土氧化物 热发射 寿命 发射机理 

分 类 号：O462[理学—电子物理学]