Dose detective

New portable radiation sensor technology will allow emergency teams to measure the level and source of radioactivity more accurately, its UK developers claim.

Called the isotopic personal dosimeter (IPD), the unit is designed to replace conventional Geiger counter radiation detection devices. It is more sensitive and offers a greater dynamic range, according to engineers working on the project.

The IPD is being developed by Cambridge Design Partnership (CDP) for Isle of Wight-based radiological monitoring specialist Radiation Watch. CDP said the first version of the IPD will be used as a personal dose meter.

A local fire department in the US, with whom the developers are at an advanced stage of discussions, is likely to be the first user. There has also been interest from potential users in the UK and Japan.

The first version of the IPD, which has been designed to be wearable and rugged enough to withstand use in emergency situations, contains a cadmium telluride pixelated sensor, which sits on a bed of silicon. When photons hit the cadmium telluride, electrons are released. These are collected by the silicon, which behaves in a similar fashion to a camera. But instead of capturing light, the device measures photons.