# Thermal-Assisted Field Emission Characteristics of Carbon Nanotubes and Application in Pulsed X-Ray Imaging

## TL;DR

This paper explores how carbon nanotubes can be used for stable and efficient pulsed X-ray imaging by improving their electron emission performance.

## Contribution

The study introduces a thermal-assisted field emission mode for carbon nanotubes that enhances emission stability and enables high-speed X-ray imaging.

## Key findings

- Thermal-assisted operation reduced current fluctuations in carbon nanotube emission to below 1%.
- CNT cathodes achieved microsecond-scale pulse response and lower power consumption compared to traditional cathodes.
- Pulsed X-ray imaging at 100 μs intervals clearly visualized rotating blades at 600 Hz.

## Abstract

Carbon nanotube (CNT) cathode materials exhibit excellent electron emission performance and have become a key research focus in the field of vacuum electronics. However, their practical applications are still restricted by challenges, including emission instability and ambiguity in temporal resolution capability. This work investigated the thermal-assisted field emission characteristics of CNT and their application in pulsed X-ray imaging. Systematic characterization of the turn-on field strength, emission stability, pulse response characteristics, and pulsed X-ray imaging performance demonstrated that the thermal-assisted operating mode reduced current fluctuations to below 1%. Increasing the heating power further enhanced emission stability and lowered the turn-on field strength. In thermal-assisted pulsed emission mode, CNT cathodes exhibited reduced power consumption compared to conventional thermionic cathodes and achieved microsecond-scale pulse response. Further X-ray imaging experiments confirmed that the X-ray dose generated by CNT in this operational mode exhibited higher stability, enabling 100 μs pulsed imaging and clear visualization of rotating blades operating at 600 Hz. This study validated the feasibility of CNT cathodes for high-speed X-ray imaging and could provide a reference for the development of advanced pulsed X-ray sources and related technologies.