采用丝网印刷法制备了一种大面积的碳纳米管阴极,表征了阴极表面碳纳米管的形貌及分布.研究了该阴极在不同脉冲条件下的高压脉冲发射特性,分析了发射时阴极面等离子体产生和发射点的分布.研究表明:碳纳米管阴极的脉冲发射机制为爆炸电子发射,在平均场强为16.7V/μm的单脉冲电场下,阴极的最高发射电流密度为99A/cm^2.在平均场强为15.4V/μm的双脉冲电场下,阴极的最高发射电流密度为267A/cm^2.碳纳米管阴极可以作为强流电子束源在高能微波器件中得到应用.
A high-intensity cold cathode based on field emission from multi-walled carbon nanotubes was fabricated by screen-printing. The high intensity was obtained when the cathode was subjected to a pulsed electric field. The emission properties of the cathode were investigated in both single-pulse and double-pulse mode experiments. Emission photos of the cathode surface were investigated, and the pulsed emission mechanism of the carbon nanotube was explosive electron emission. In the single-pulse mode, the field emission current density is 99 A/cm^2 at an applied electric field of 16.7 Vμm. In the double-pulse mode, the emission current density can reach 267 A/cm^2 at an applied electric field of 15.4 V/μm. This carbon nanotube cathode appears to be suitable for high-power microwave device applications.