RELIABLE CARBON NANOTUBE BASED MICRO WIRE FOR MICRO FOCUS FIELD EMISSION X-RAY SOURCE BY MICROMACHINING

This paper reports the design and characterization of a CNT based field emission x-ray source that affords a high spatial resolution. This work builds on a method reported at IEEE MEMS 2016, which was mainly focused on the fabrication process and material characterization. This paper will unveil more experimental results using for micro focus field emission x-ray source. A simplified imaging system was built to measure the x-ray focal spot size based on the pinhole imaging. Thanks to the effective direct contact and the strong interactions between CNTs and the substrate, field emission current of 1.11 mA could be achieved from the micro wire. Moreover, a stable effective elliptical focal spot size (30x120 um(2)) can be obtained from experimental measurements using such design. Due to the small focal spot size obtained from the micro wire, clear radiographic images of 30 um bars were achieved.