为研究场致发射的温度效应对微波管中爆炸电子发射过程的影响, 在对比分析低温条件下的场致发射电流密度Fowler-Nordheim(FN)和一般的电子发射电流密度积分公式的基础上, 利用细长圆柱形微凸起模型, 重点考虑焦耳加热和热传导两个因素, 编程计算得到了微凸起内部的温度分布和不同位置处温度随时间的变化。结果表明:场致发射的温度效应是一个重要影响因素, 考虑温度对场致发射的影响后, 微凸起内部各点的温度随时间呈非线性增长, 且增长速率越来越大; 在微波电场强度较弱时, 若不考虑场致发射的温度效应而直接用FN公式表示的电流密度代入计算, 会使爆炸发射延迟时间变短; 当微波电场很强时, 温度效应对爆炸发射延迟时间的影响则较小。

The paper drew a comparison between the Fowler-Nordheim (FN) field emission current density which is applicable at low temperature and the general integral expression for field emission current density. A slender cylindrical microprotrusion model was adopted, two main factors-joule heating and heat conduction were both taken into account, and the temperature distribution in microprotrusion and the time-dependence of temperature at different points on microprotrusion were obtained using the code developed by ourselves. The results show that it is necessary to consider the influence of temperature effect of field emission on explosive electron emission. The temperature in microprotrusion increases nonlinearly with time when the temperature effect is included, and the increasing rate of the temperature grows more and more quickly. At low microwave electric field, the time delay of explosive electron emission will be shortened if the FN current density of electron emission is used instead of the general integral expression which can include the temperature effect of field emission; the temperature effect has little influence on time delay of explosive electron emission at high microwave electric field.