Nuclear Techniques ›› 2015, Vol. 38 ›› Issue (11): 110202-110202.doi: 10.11889/j.0253-3219.2015.hjs.38.110202

• LOW ENERGY ACCELERATOR, RAY AND APPLICATIONS • Previous Articles     Next Articles

Comparative analysis and measurement of focus spot for X-ray source

SUN Chaoming TANG Guangping LI Qiang WANG Zengyong   

  1. (Institute of Machinery Manufacturing Technology, China Academy of Engineering Physics, Mianyang 621900, China)
  • Received:2015-06-02 Revised:2015-10-19 Online:2015-11-10 Published:2015-11-13

Abstract: Background: Image quality in radiographic testing is often conditioned by the size and distribution of X-ray source. However, determination of focal spot is not performed effectively in practice, thus it is difficult to accurately control the image quality in the testing. Purpose: This study aims to obtain a quick and efficient test method to evaluate the focal spot for X-ray source. Methods: Test tools such as pinhole plate, star test pattern and duplex wire image quality indicator (IQI) were used to measure the focal spot of a portable X-ray source separately. Several measurements were carried out and compared in details. Results: Results of star test pattern and duplex wire IQI were coincident, but different from the results of pinhole imaging method obviously. Conclusion: Nominal focal spot size of an X-ray source may be considerably different from that in practice use, so it is necessary to timely evaluate characteristics of the focal spot. The duplex wire IQI can usually replace star test pattern to measure un-sharpness in radiographic testing images and to evaluate focal spot size.

Key words: Focal spot, Test and measurement, Pinhole imaging, Star test pattern, Duplex wire IQI