MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY
Geiger-Muller tube. Experimental set-up showing a Geiger-Muller tube (lower left) for detecting levels of radiation. The power supply and display box are seen at centre. Mounted in its holder, a few centimetres in front of the tube, is a sample of a radioactive material. The holder is required to minimise dangerously close contact. The tube contains a gas which is ionised by the energetic radiations produced by the sample. This sets up a cascade of electrons, resulting in an electric pulse. The tube counts these pulses and displays the number of radioactive particles detected per second. The ruler allows the fall in radiation exposure with distance to be investigated.
Model release not required. Property release not required.