Using Kromek radiation detectors to map the Chernobyl Red Forest
Using a combination of Sigma scintillation detectors, GR1 CZT based gamma spectrometers and TN15 thermal neutron detectors attached to a variety of flying drones a team from Bristol University and the NCNR (National Centre for Nuclear Robotics) spent some time in the Chernobyl area mapping the radiation “landscape” of the Chernobyl Red Forest area near the surrounding the Chernobyl Nuclear Power Plant within the exclusion zone.
Fixed-wing drones used to map the main area
Kromek radiation detectors were used on a fixed-wing drone, essentially a small remote control aeroplane, to quickly cover the 10-square-kilometre (4 sq mi) area. The fixed-wing drone carried two Kromek Sigma-50 gamma radiation detectors. These use CsI(Tl) thallium activated caesium iodide crystals and replace the usual photomultiplier systems with state of the art SiPMs. This offers up to 32.8 cm3 of detector volume, delivered in a small palm-sized package.
Rotary wing drones used to provide detail radiation analysis of hotspots
Once the area was mapped the team used helicopter-style drones to examine any areas of interest. A rotary UAV is perfect for getting close to a place of interest and can hover allowing the radiation detectors time to get a detailed reading. The rotary drones usually carry one detector either a Sigma-25 or 50 or a GR1 gamma spectrometer. The GR1 uses solid-state CZT crystals in the unit giving the radiation researcher a whole gamma radiation spectrometer in a tiny unit measuring: 25mm x 25mm x 63mm (about the size of a large lipstick).
You can read the full story here and see a video of the mapping: Chernobyl Red Forest radiation mapping user story.