Study on a microfocus X-ray source with a directly-grown CNT field emission cathode

With the increasing demand for high-precision imaging in medical diagnostics and industrial inspection, developing miniaturized, long-life microfocus X-ray sources has become an important research topic. In this work, we successfully fabricated carbon nanotube (CNT) cathodes on nickel alloy substrates via chemical vapor deposition, achieving exceptional field emission performance with a low turn-on field of 1.01 V/μm and good operational stability. Furthermore, a single-focus electron gun structure was designed and developed based on electromagnetic field simulations. Parameter optimization of key electrodes enabled high-quality imaging with a spatial resolution of 12 lp/mm (42.1 μm), showing good agreement between experimental results and simulation data.