A carbon nanotube field emitter formed on W-wire with high current density for X-ray source

Field emission micro-focus x-ray source based on carbon nanotube (CNT) has attractive features for biomedical or clinical imaging [1]. X-ray sources for micro-focus and/or miniature tube types require a mini-sized, high-density emission current in the order of 10
²
∼10
³
mA/cm
²
. We have previously reported that the optimized paste composition with a nano-scale metal filler enhanced adhesion between CNT emitter and cathode electrode at low temperature [2]. In this study, a CNT-on-Tip cathode, having CNT emitter on a tungsten (W) wire of 100 µm in diameter, was developed in order to increase emission current density.