高亮度小型液态金属Ga离子源

A Small Type of Ga LMIS with High Brightness

本文介绍高亮度小型液态金属Ga离子源。本源在5.5kV的引出电压下总发射电流可达250μA,发射阈值电压低至1kV(发射体针尖到引出极膜孔中心的距离固定在2mm左右)。在1.33×10^(-6)Pa的真空度下测量源的发射特性,并对Taylor锥发射模型作了初步探讨。通过对发射体基底尖端进行特殊的铬合处理,可有效地增大发射电流,提高发射稳定性。整个系统封装在直径为55mm的玻壳内;发射体尖端与引出极间距离采用一特殊柄在0.5～5mm范围内在管外调节。

In this paper we report a small type of Ga LMIS with high brightness which we have designed. The total emission current can be reached as high as 250 μA at the extractive voltage of 5.5 kV. The emission threshold voltage as a low as 1 kV. (Where the distance between the emitter tip and the extractive electrode is maintained at about 2 mm.) The emission characteristics of Ga source has been measured at the pressure of 10-6 Pa and the result is satisfactory. We have simply discussed on the so called Taylor Cone model. The emission current and stability can be increased effectively by special treatment to the emitter tip. The whole system is fixed in a glass tube of diameter 55 mm, where the distance from emitter tip to the extractive electrode can be adjusted in the range of 0.5-5 mm outside the tube by using a special rotator.