Year
2005
Abstract
Many radiation detection systems currently deployed for counter-terrorism applications detect only gamma radiation. Although recommended by both the IAEA and the U.S. DHS, widespread use of neutron detection equipment has been historically limited because of high costs and technical complexities. Superheated droplet technology offers high sensitivity for detection of neutrons and low sensitivity to gamma rays, is low cost, and can be used effectively with little or no training. The detector consists of a clear, pocket-sized tube filled with a polymeric gel that contains tiny droplets of a superheated detector liquid. When a neutron interacts with a droplet, the superheated liquid vaporizes and forms a visible gas bubble that is trapped in the gel. The number of bubbles is directly proportional to the amount of neutron radiation; hence, the device provides a quantitative, real-time measurement of radiation exposure. The bubble detectors are reusable. After independent work on electronic readout technology and its integration with communications technology, BNL became a participant in the Defender Nuclear Detection Web project, a unique international collaboration organized by the Canadian developer of superheated droplet technology, Bubble Technology Industries Inc, and supported by the Government of Canada through its Chemical, Biological, Radiological and Nuclear Research & Technology Initiative (CRTI). Defender™ neutron detectors will be electronically instrumented with a digital readout, alarm capability, GPS and wireless communication for transmission of data to a central command center. The detectors will then be interfaced to a data management network that will enable the radiation readings from a broad geographical area to be monitored in real time. BNL will test the system using protocols developed for DHS to evaluate radiation equipment before its deployment in the New York City area and elsewhere. If successful, the Defender system will provide neutron-detection technology of sufficiently low cost for wide deployment in homeland security and counterterrorism applications along both coasts of North America and along the US-Canada border. BNL work with these technologies and the status of the CRTI collaboration will be presented.