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JAXA Creates Camera That Can See Radiation
New submitter Ben_R_R writes "The Japan Aerospace Exploration Agency has created a camera that can 'see' radioactive contamination by detecting gamma rays emitted by radioactive cesium and other substances. The camera has been tested in the disaster evacuation zone around Fukushima. The image captures levels of radiation in six different colors and overlays the result over an image captured with a wide angle lens."
So where is the data on how accurate it actually is? How does it work???
For example, this is informative.
http://imagine.gsfc.nasa.gov/docs/features/exhibit/glast_exhibit.html
TFA about this device is useless.
When I readed the topic, I just tought "Oh, someone invented Camera what can see light, AMAZING!"
Of course I know it was only about ionizing radiation and not just anykind radiation like visible light.
Usually, you just put a scintillating crystal, e.g. thallium-doped sodium iodide, in front of your detector. Gamma photon hits crystal, crystal emits photon in the visual range, photomultiplier detects visual photon. TFA is somewhat silent on how this differs from your run of the mill gamma camera which has been known for half a century by now.
Ubi solitudinem faciunt, pacem appellant.
Oh great, now we're going to be overwhelmed with Japanese tourists taking pictures of radioactive things!
Shot 1: Dad and the kids smiling at camera and glowing in dark.
Shot 2: Look! Our Toyota doesn't need headlights!
Shot 3. Mr. Fujimoto and his radioactive shoes!
Shot 4. Godzilla. No, really, Godzilla. Run!
The big difference is that a scintillator or geiger tube is equivalent to a simple eye that just detects light levels. That can't be used to create a usable image. I suspect they have something like an insectoid compound eye going on.
Geiger counters tell you if there's radiation at the counters sensor. This lets you measure/see where the radiation is coming from.
Scintigraphy is not only used for mere detection, but is in routine clinical use for imaging. You can go the pinhole route, but usually go with a movable collimator and movable detector, scanning the image. Now, if those guys have something that can snap a picture just like an optical camera, that would be interesting - but TFA is unfortunately silent on the details.
Ubi solitudinem faciunt, pacem appellant.
On one picture you can see how the visual image and the gamma radiation agree at the corner of a wall. You can see that the radiation spot turns 90 degrees with the bottom edge of the wall and how the radioactive materials kind of puddled near the bottom of the wall. It's cool to see that the two images agree.
Also there is video of the actual camera which is pretty big and not so portable. You probably want to keep it in a car most of the time.
http://www.japanprobe.com/2012/03/30/camera-can-see-radiation/
The English article edited out some information that was in the Japanese article.
Currently it doesn't tell you the precise amount of radiation being emitted but you get an idea of the highs and lows from it.
The technology that was developed for a detector installed in Japan's next-generation astronomical observatory satellite, the Astro H, to observe gamma ray bursts caused by astronomical events such as old stars exploding into supernovae. JAXA's Professor Tadayuki Takahashi who developed it says, "I want to aim at making this a practical tool quickly." And here is the Prof. Takahashi's cool page and Japanese version which shows news items too.
You will find several English papers on his work by Google: "High-Resolution CdTe Detectors and Application to Gamma-Ray Imaging"
Finally there are links from the Japanese page to a lot of detailed info about the gamma ray camera, though in Japanese there are PDFs including with photos of the supermarket experiment: here,pdf 1. pdf2, here.