Car-borne search and identification measurements with Detective 200 devices

Radioactive or nuclear material could fall into the wrong hands and pose a serious threat to society. In such cases it is very important to localize the material as soon as possible. With an indication by third parties limiting the relevant area it is most effective to search my means of a vehicle which carries appropriate detectors. Fraunhofer INT has long time experience with car-borne searching and has equipped a station wagon called DeGeN with gamma and neutron detectors. The neutron component is realized by slab counters incorporating ³He tubes and the gamma component by two scintillators with NBR functionality. As optional detector a portable electrically cooled Germanium detector (Detective) is included for identification. It is used for inspection directly from the vehicle and as hand-held device on-site. AMETEK/ORTEC has recently developed Detective-Remote software which combines data from different Detective devices. It shall enable the user to localize and identify radioactive and nuclear sources while driving. During a measurement campaign a car was equipped with two Detective 200 devices. Inside a test area sources were searched, without any information about the type, strength, number of placement of the sources. The present paper introduces the test area where the measurements have been carried out and presents the results obtained with the vehicle equipped with the Detective 200 devices using the Detective-Remote software. Limits and weak points of the software will be addressed as well as the strengths of the system. The search was carried out also by use of the INT measurement car DeGeN and a comparison with the use of germanium as detector material for search purposes is drawn. The measurements took place at the Institute of the fire brigade (IdF) in Muenster, Germany. The Detective measurement system has been provided by AMETEK/ORTEC.