The camera superimposes two images: a standard black and white image, and a 16-by-16 coloured grid.
Image of Fukushima Daiichi unit 1 airlock taken by gamma camera
Gamma camera view of the same image, showing radiation intensity
The coloured grid is created by a 16×8 array of CdTe semi-conductor gamma detectors (interpolated by software) aimed at the same focal plane as the digital camera. Toshiba would not say exactly how they are arranged inside the camera to produce the image. The intensity of the gamma reading, and hence the shades of the colour scale, is not absolute, but can be customised by users. Toshiba declined to specify the energy sensitivity of the device.
Minimum standoff distance is 0.75 m. The refresh rate of the device is 1.5 seconds/image. In use, the camera is set up on a tripod and connected to a PC, from which it is operated, and to which it saves the photographs.
Toshiba gamma camera
Toshiba gamma camera in use
The camera was developed for decommissioning work in Japan, and Toshiba teams are using it to help the process; this is the urgent priority, a Toshiba spokesman said; commercial sales can come later.
