钛掺杂氧化镁薄膜二次电子发射倍增特性研究

The secondary electron emission multiplication characteristics of titanium-doped magnesium oxide thin films

氧化镁具有较高的二次电子发射系数,适合作为制备多级放大装置的二次电子发射材料。文章采用磁控溅射法制备高质量氧化镁薄膜和钛掺杂氧化镁薄膜,并对薄膜进行形貌表征,研究其二次电子发射倍增特性,包括氧化镁薄膜电子倍增器的增益特性以及增益衰减情况。结果表明:高压源电压和电流的增大均可提高电子倍增器的电流增益倍数;掺杂Ti不仅能提高电子倍增器的增益效能,且相比纯氧化镁薄膜,钛掺杂氧化镁薄膜的增益衰减明显放缓,能够将倍增器的寿命延长2倍以上。

The magnesium oxide,due to its high secondary electron emission coefficient,is suitable as a secondary electron emission material for the preparation of multi-stage amplification devices.In this paper,the high-quality magnesium oxide films and the titanium-doped magnesium oxide films are prepared by the magnetron sputtering,and the morphology of the films is characterized.In addition,the secondary electron emission multiplication characteristics of the films used in the MgO film electron multiplier are studied.The gain characteristics and the gain reduction of the electron multiplier are also analyzed.It is shown that the increase of the voltage or the current of the high voltage source can both increase the current gain multiple of the electron multiplier;the titanium doping,for example,the Ti-doped MgO film in comparison with the pure MgO film,can not only increase the gain of the electron multiplier,but also extend the working life of the multiplier more than two times.