金刚石薄膜中二次电子输运的蒙特卡罗模拟

本文通过编写的二维MATLAB蒙特卡罗程序, 对倍增的二次电子在金刚石薄膜中的输运特性进行了初步模拟. 研究表明: 二次电子的迁移率对温度和外加电场的大小很敏感, 在杂质浓度比较低时(<10¹⁷/cm^-3)受杂质浓度的影响不大. 模拟得到的 二次电子的饱和速度为1.88×10⁷ cm/s, 无外加电场时的迁移率为3732 cm² /V.s. 同时, 通过对二次电子束团在金刚石薄膜中的整体输运特性的模拟, 证明了束团电荷密度在应用要求的范围内时, 空间电荷力的影响可以忽略不计.

A Monte Carlo simulation of secondary electron transport in diamond

The diamond-amplifier photocathode (DAP) offers a new widely applicable way to generate high average-current, high brightness, and low thermal emittance electron beams. Physical processes with multiple parameters are important for the design of a reliable and efficient DAP. To perfom a study in-depth, a 2D Monte Carlo model in MATLAB frame is built to simulate the secondary electron transport in diamond. This simulation gives some proofs that the drift velocity is sensitive to diamond temperature and electric field applied, but not sensitive to the low impurity density(<10¹⁷/cm^-3). As an appropriate result, the saturation velocity of secondary electron reaches 1.88?10⁷ cm/s, and mobility without applied field is 3732 cm² /V.s. In addition, some properties of a secondary electron bunch transported in diamond are discussed, which indicate that the effect of space charge under our considered electron cloud density is small.