On March 29th, the Japan Aerospace Exploration Agency (JAXA) and the Japan Atomic Energy Agency announced that they have developed a prototype camera which detects gamma-ray emitting radioactive material such as cesium and shows the exposure distribution over an image. They hope that it can be used to make clean-up of contaminated areas around Fukushima Daiichi more efficient by locating places where radioactive matter has accumulated.
Gamma ray detectors used at accident sites have existed for some time, but this new prototype is said to be capable of much more precise readings. Using a wide-angle lens, the camera records an image and measures levels of cesium 137 and 134. The distribution is then shown on the image, using six different colors. In February, the prototype was tested in Itate Village in Fukushima Prefecture. Scientists measured radiation levels around supermarkets, roads and other public places to test the camera’s capabilities. At present, it measures not the absolute levels, but the relative levels by looking at highs and lows.
You may be wondering how JAXA got involved with this project. The technology used in the camera was developed as part of the next-generation astronomy satellite ASTRO-H, which will be equipped with a gamma-ray detector to observe the gamma bursts produced by dying stars going supernova. According to JAXA’s Dr. Tadayuki Takahashi, who invented the technology, “We are aiming to quickly turn this technology to practical use.”