Discovery of X-rays

In 1895 Wilhelm Röentgen discovered X-rays. Studying the light emissions from an electric discharge tube, he observed that a screen covered with a fluorescent salt flashed every time he switched on the discharge tube. It was clear to Röentgen that the cathode rays were emissions that could not pass through the glass tube, yet for some reason, “invisible” radiation passed through the walls and impacted the screen. He also found that the penetrating power was surprising. He placed certain obstacles between the screen and the emission (metals, wood, glass, etc.) and yet the luminosity persisted. He assumed that it was high energy radiation but of an unknown nature. For this reason he called it X-radiation. It was not until 1912 that the German physicist Max Von Laue determined the electromagnetic nature of X-rays.

Properties of X-rays

  • They are electromagnetic radiations.
  • They propagate in a straight line at the speed of light.
  • It is impossible to deflect their trajectory by means of a lens or prism, but they can be deflected by a crystalline lattice (ray diffraction).
  • They are ionizing radiation (they ionize gases).
  • They can destroy living cells.
  • They pass through matter.
  • The degree of penetration depends on their energy and the nature of the medium they pass through.

Video about the Discovery of X-rays