Nuclear Techniques ›› 2020, Vol. 43 ›› Issue (3): 30203-030203.doi: 10.11889/j.0253-3219.2020.hjs.43.030203


X-ray tube with variable focal spots based on field emission of carbon nanotubes cathode

Huaping TANG1,3,Zhiqiang CHEN2,3,Ang LIU1,Zhanfeng QIN1,Wu HE1,Qinghui ZHANG1   

  1. 1.NuRay Technology Company Limited, Changzhou 213000, China
    2.Department of Engineering Physics, Tsinghua University, Beijing 100084, China
    3.Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084, China
  • Received:2019-10-17 Revised:2019-11-28 Online:2020-03-15 Published:2020-03-24
  • About author:TANG Huaping, male, born in 1976, graduated from Tsinghua University with a master's degree in 2002, focusing on electron linac and carbon nano cathode X-ray source
  • Supported by:
    National Science Foundation for Distinguished Young Scholars(11525521)

Abstract: Background

Mobile digital radiography (DR) is a hot research direction in the field of modern medical imaging.


This study aims to develop a new-type X-ray tube for mobile DR devices.


Firstly, in order to solve the problems of slow start-up and high dose of ineffective radiation of hot cathode ray tube, carbon nanotube (CNT) was employed to replace traditional filament as the cathode of the X-ray tube. Then flexible adjustment of focal spot size was realized through active focusing mechanism, so as to meet various clinical application needs. Finally, experimental tests were carried out to compare with the simulation results.


Both the simulation and experimental results show that the maximum anode voltage of the finally built X-ray tube is 110 kV, the maximum anode current is 70 mA, and the focal spot size varies between 0.9 and 1.9 (IEC 60336 nominal focal spot value). The different working parameters of the corresponding X-ray tube in four different clinical application scenarios are given.


The X-ray tube has many advantages, such as fast startup, low power consumption, and wide application scenarios, which makes it very suitable for mobile DR devices.

Key words: Carbon nanotube cathode, Cold-cathode X-ray tube, Variable focal spots, Mobile digital radiography

CLC Number: 

  • TL99