【摘要】 一种基于碳纳米管场发射阴极阵列的大功率脉冲X射线管研制成功。该X射线管中采用由微波等离子体化学气相沉积方法制备出的高度定向的、具有优异场致发射性能的碳纳米管阵列作为X射线管的冷阴极,该阴极阵列可以实现超过280mA的总发射电流,相应的发射电流密度为2.8A/cm~2。并根据场致发射阴极特点设计出了由六边形钼网为栅极的多级式栅控型高分辨率电子光学系统,在阳极靶角为14°的情况下,其等效的X射线的焦斑尺寸约为0.24mm×0.22mm。对实物进行X射线成像测试表明,可以实现直径为0.1mm标准钨线的清晰成像,其他物体成像层次感也非常优异,可以满足工业和医疗X射线成像的应用。更多还原

【Abstract】 A high-power pulse X-ray tube based on carbon nanotube(CNT)field emitters has been developed,in which a highly directional carbon nanotube array with excellent field emission property prepared by microwave plasma chemical vapor deposition was employed as the cathode.An emission current more than 280 mA was achieved from the CNT cathode,the corresponding current density was more than2.8 A/cm~2.To obtain high definition X-ray image,we designed a grid-controlled electron gun in which a high convergence electron lens was optimized.The simulation results showed that the equivalent X-ray focal spot size on the target with 14°angle was about 0.24 mm×0.22 mm.The X-ray images stated that a tungsten wire with diameter of 0.1 mm could be showed clearly.This CNT emitter based X-ray tube can meet the need of many applications for industrial and medical X-ray systems.更多还原