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Title: Data acquisition and analysis of the UNCOSS underwater explosive neutron sensor

Journal Article · · IEEE Transactions on Nuclear Science
; ;  [1]; ; ; ; ; ; ;  [2]
  1. CEA, DEN, Nucl Measurement Lab, F-13108 St Paul Les Durance, (France)
  2. CEA, DRT, LIST, F-91191 Gif Sur Yvette, (France)

The purpose of the FP7 UNCOSS project (Underwater Coastal Sea Surveyor, http://www.uncoss-project.org) is to develop a neutron-based underwater explosive sensor to detect unexploded ordnance lying on the sea bottom. The Associated Particle Technique is used to focus the inspection on a suspicious object located by optical and electromagnetic sensors and to determine if there is an explosive charge inside. This paper presents the data acquisition electronics and data analysis software which have been developed for this project. A field programmable gate array that digitizes and processes the signal allows to perform precise time-of-flight and gamma-ray energy measurements. The gamma-ray spectra are unfolded into pure elemental count proportions, mainly C, N, O, Fe, Al, Si, and Ca. The C, N, and O count fractions are converted into chemical proportions, taking into account the gamma-ray production cross sections, as well as neutron and photon attenuation in the different shields between the ROV (Remotely Operated Vehicle) and the explosive, such as the explosive iron shell, seawater, and ROV envelop. A two-dimensional (2D) barycentric representation of the C, N, and O proportions is built from their chemical ratios, and a 2D likelihood map is built from the associated statistical and systematic uncertainties. The threat level is evaluated from the best matching materials of a database including explosives. (authors)

OSTI ID:
22274004
Journal Information:
IEEE Transactions on Nuclear Science, Vol. 59, Issue 4; Other Information: Country of input: France; 19 refs.; This record replaces 45095237; ISSN 0018-9499
Country of Publication:
United States
Language:
English