[Development of cloud chamber having thin-film entrance windows and proposal of practical training for beginners using X-ray equipment and unsealed radioactive material]

Nihon Hoshasen Gijutsu Gakkai Zasshi. 2014 Jan;70(1):26-33. doi: 10.6009/jjrt.2014_jsrt_70.1.26.
[Article in Japanese]

Abstract

A cloud chamber is a detector that can visualize the tracks of charged particles. Hayashi, et al. suggested a visualization experiment in which X-rays generated by diagnostic X-ray equipment were directed into a cloud chamber; however, there was a problem in that the wall of the cloud chamber scattered the incoming X-rays. In this study, we developed a new cloud chamber with entrance windows. Because these windows are made of thin film, we were able to direct the X-rays through them without contamination by scattered X-rays from the cloud chamber wall. We have newly proposed an experiment in which beta-particles emitted from radioisotopes are directed into a cloud chamber. We place shielding material in the cloud chamber and visualize the various shielding effects seen with the material positioned in different ways. During the experiment, electrons scattered in the air were measured quantitatively using GM counters. We explained the physical phenomena in the cloud chamber using Monte Carlo simulation code EGS5. Because electrons follow a tortuous path in air, the shielding material must be placed appropriately to be able to effectively block their emissions. Visualization of the tracks of charged particles in this experiment proved effective for instructing not only trainee radiological technologists but also different types of healthcare professionals.

Publication types

  • English Abstract

MeSH terms

  • Beta Particles
  • Molecular Imaging / instrumentation*
  • Monte Carlo Method
  • Radiography / instrumentation*
  • Radioisotopes
  • Teaching
  • Technology, Radiologic / education*

Substances

  • Radioisotopes