X-ray ultrashort pulse emission characteristic of carbon nanotube cold cathode X-ray source by pulse driving mode

Abstract

In the present work, we build a triode structure of carbon nanotube (CNT) cold cathode X-ray source driven by pulse voltage in dynamic vacuum system. The results show that the grid voltage and pulse width affect the amplitude, delay time and relative pulse spread of X-ray. The X-ray emission delay time decreases sharply from 102 to 75 ns when the grid voltage increases from 600 to 650 V. The relative pulse spread tends to be saturated with approximately 350 ns (±20 ns) when the voltage increases from 600 to 650 V. The theoretical limit frequency of this X-ray pulsed emission system is approximately 2.86 MHz (1/350 ns). This work reveals the ultrashort pulse emission characteristics and affecting factors of CNT cold cathode X-ray source, promoting the development of CNT cold cathode X-ray source in pulse application.