A field emission nano-focus x-ray source with effective electron beam focusing module

We developed a field emission nano-focus x-ray source using carbon nanotube (CNT) emitters and electron beam (E-beam) focusing modules, which could be used in the applications requiring the high-resolution x-ray images. For the nano-size focusing of E-beam from CNT emitters, we designed special focusing modules consisting of electrostatic and magnetic lenses. The geometries and operating conditions of focusing modules were optimized to give the desired demagnification characteristics by performing the electron optics simulations of the designed x-ray source under external electric and magnetic fields. We constructed and operated an open-type nano-focus x-ray system using the focusing modules under a high-voltage condition to attain the high-resolution x-ray images. The results showed a possibility of field emission nano-focus x-ray sources with a relatively high current and controllable magnification through the effective focusing modules.