W[111]尖端场发射电子枪的工作特性

本文报道了单晶W111]尖端的制作,以及由W111]尖端阴极,第一、二阳极组成的三极场发射电子枪(FEG)的工作特性。实验结果表明,这种FEG在枪室真空为510-7Pa,加速电压在30kV的条件下,其虚源半径为1.6nm;亮度为3.8109A/cm2.sterad;场发射电流为1A时,束流稳定性为5%(10min内)。说明它是一种较理想的点状电子源,在实际应用中具有广泛发展前景。

OPERATING CHARACTERISTICS FOR A FIELD EMISSION GUN WITH W[111] TIP

The fabrication method of W111] tip and the operating characteristics ofa field emission gun (PEG) which consists of W111] tip, first and second anodes are reported. Experimental results show that on condition that the vacuum in the gun chamber is better than 510-7 Pa and acceleration voltage is 30kV, the finite radius of the virtual source of the FEG is 1.6nm, and the brightness of FEG is estimated as 3.8109 A/cm2, sterad; on condition that the field emission current is 1A, the stability of beam current is better than 5% in 10 min. It is able to be used in scanning electron microscopesand electron probe system etc.