同心圆环型场发射阵列阴极的粒子模拟

SIMULATION OF IN PLANE LENS FIELD EMISSION CATHODES

模拟了同心圆环型场发射阵列阴极的特性。采用时域有限差分法计算了电场，利用Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ方程计算锥尖处的发射电流，利用Ｌｏｒｅｎｔｚ方程计算了电子的运动轨迹。得到了微阴极电子的运动轨迹、相空间图以及电子束的发散度、亮度等，结果表明该结构能形成良好的聚焦电子束。

The performance of an in plane lens field emission cathode, based upon a unit cell with a conical field emitter tip, gate, in plane lens, and anode, are evaluated via MAGIC particle in cell simulation code. Electron emission is calculated from the Fowler Nordheim equation. The trajectories and phase space were evaluated, the normalized beam emittance ε n = 1.0 9×10 -9 m·rad and brightness B n = 3.79×10 -9 A/(m·rad) 2 for a typical in plane lens Field Emission Cathodes.