等离子喷涂含钪氧化物阴极制备及发射特性研究

在三元碳酸盐中加入微量钪,利用大气等离子喷涂方法制备出含钪等离子喷涂氧化物阴极. 制备过程中,在三元碳酸盐原来配比基础上增加12%—22%(摩尔百分比)的碳酸钡进行混合, 并将该混合物进行造粒,在造粒过程中加入微量的钪.利用扫描电子显微镜分析了等离子喷涂材料的形态 和分布,表明符合等离子喷涂对粉末大小和形状的要求,并解决了等离子喷涂过程中钡的损失问题. 对这种新型氧化物阴极的分解排气过程进行详细分析,结果表明,排气时这种阴极比普通喷涂阴极出气少 且分解时间短.对发射性能及寿命进行测试,结果显示这种新型氧化物阴极的性能显著提高,阴极寿命延长.

Preparation and emission characteristic study of plasma-sprayed scandia-doped oxide cathode

Plasma-sprayed scandia-doped oxide cathode is prepared by doping a small amount of scandia into the triple carbonates and employing the air plasma spraying technique.In the preparation process,a small amount of scandia is added in the shaping process of mixing the triple carbonates with an additional 12%—22%of BaCO₃（molar ratio）.The shape and the distribution of the feed material analyzed by using scanning electron microscope show that the size and the shape of the feed material meet the requirement for plasma-spraying and that it fully compensates the loss of barium in the plasma-spraying process.The analysis of the decomposition process shows that scandia-doped plasma-sprayed oxide cathode has a shorter process of decomposition and less exhausted gas amount than the commonly-used oxide cathode.The test on the emission performance of the new type oxide cathode shows that the emission performance of scandia-doped plasma-sprayed oxide cathode is much better than that of commonly-used oxide cathode and that the life time of the former is longer than that of the latter.