热电子阴极单晶LaB_(6)制备工艺及发展研究

The Preparation Process and Development Analysis of Single Crystal LaB_(6)for Thermionic Cathode

单晶六硼化物LaB_(6)具有优异的热电子发射性能和化学稳定性,是空间用热电子阴极发射源的理想材料,具有优良的发射效率及寿命。随着空间电推进系统高功率、长寿命的航天任务的实施,大尺寸、低成本、高纯度单晶LaB_(6)制备技术研究显得愈发重要。在调研国内外LaB_(6)基体研制技术的基础上,结合单晶LaB_(6)主流制备技术,针对我国空间电推进应用需求,分析了晶体制备过程中存在的关键技术及难点,提出开展空间用单晶LaB_(6)工程化研制的初步建议。

Single crystal hexaboride LaB_(6)has excellent hot electron emission performance and chemical stability.It is an ideal material for space thermionic cathode emission sources,which directly affects its emission efficiency and lifespan.With the demonstration of high-power and long-life space missions for space electric propulsion systems,the preparation technology of large size,low-cost,and high-purity single crystal LaB_(6)is becoming increasingly important.Based on the research on the development process of LaB_(6)matrix both domestically and internationally,combined with the preparation technology of single crystal LaB_(6),aiming at the application requirements of space electric propulsion,the key technologies and difficulties in crystal preparation are analyzed.Some suggestions for the engineering development of single crystal LaB_(6)are put forward.