On-line determination of the water cut and chlorine impurities in crude oil using a pulsed beam of fast neutrons.

A neutron-based sensor has been developed able to measure the water cut and the chlorine content in crude oil. The sensor is based upon the use of a pulsed fast neutron source. Two different cases were studied. Case ''A'': chlorine detection with no water present and case ''B'': water cut measurements with no chlorine present. The minimum detection limits for case A and case B were found to be (62 ± 6) mg/L and (2 ± 2) vol%, respectively.

Measurement of 14MeV neutron-induced prompt gamma-ray spectra from 15 elements found in cargo containers.

Within the EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) project, the gamma-ray spectra produced in a series of materials by 14-MeV tagged-neutron beams have been collected in the inspection portal equipped with large volume NaI(Tl) detectors, in order to build a database of signatures for various elements: C, N, O, Na, Al, Si, Cl, K, Ca, Cr, Fe, Ni, Cu, Zn, Pb. The measured spectra have been compared with prediction from Monte Carlo simulations to verify the consistency of the relevant nuclear data inputs. This library of measured 14-MeV neutron-induced gamma-ray spectra is currently used in a data processing algorithm to unfold the energy spectra of the transported goods into elementary contributions, thus allowing material identification.

Monte Carlo analysis of tagged neutron beams for cargo container inspection.

Fast neutrons produced via D+T reactions and tagged by the associated particle technique have been recently proposed to inspect cargo containers. The general characteristics of this technique are studied with Monte Carlo simulations by determining the properties of the tagged neutron beams as a function of the relevant design parameters (energy and size of the deuteron beam, geometry of the charged particle detector). Results from simulations, validated by experiments, show that the broadening of the correlation between the alpha-particle and the neutron, induced by kinematical as well as geometrical (beam and detector size) effects, is important and limits the dimension of the minimum voxel to be inspected. Moreover, the effect of the container filling is explored. The material filling produces a sizeable loss of correlation between alpha-particles and neutrons due to scattering and absorption. Conditions in inspecting cargo containers are discussed.

Evaluation of elemental composition of sediments from the Adriatic Sea by using EDXRF technique.

723 sediment samples collected along the eastern Adriatic coast have been analyzed using Energy Dispersive X-Ray Fluorescence. Factor Analysis and GIS have been used for the evaluation of the resulting data base containing information on K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Br, Rb, Sr, Y, and Pb concentration levels in order to find spatial relationships in distribution of measured elements. This study can be used to identify background values and to evaluate sediment quality standards.

Quantitative comparison between experimental and simulated gamma-ray spectra induced by 14 MeV tagged neutrons.

Fast neutron interrogation with the associated particle technique can be used to identify explosives in cargo containers (EURITRACK FP6 project) and unexploded ordnance on the seabed (UNCOSS FP7 project), by detecting gamma radiations induced by 14 MeV neutrons produced in the 2H(3H,α)n reaction. The origin of the gamma rays can be determined in 3D by the detection of the alpha particle, which provides the direction of the opposite neutron and its time-of-flight. Gamma spectroscopy provides the relative counts of carbon, nitrogen, and oxygen, which are converted to chemical fractions to differentiate explosives from other organic substances. To this aim, Monte Carlo calculations are used to take into account neutron moderation and gamma attenuation in cargo materials or seawater. This paper presents an experimental verification that C, N, and O counts are correctly reproduced by numerical simulation. A quantitative comparison is also reported for silicon, iron, lead, and aluminium.

Acquisition of prompt gamma-ray spectra induced by 14 MeV neutrons and comparison with Monte Carlo simulations.

Gamma-ray spectra produced in carbon, nitrogen, oxygen, sodium, aluminium, silicon, chlorine, calcium, chromium, iron, nickel, copper, zinc, and lead by 14 MeV tagged neutrons have been collected with NaI(Tl) detectors of the EURITRACK system, which low-energy threshold has been reduced to 0.6 MeV to detect gamma rays of major elements like iron. The spectra have been compared with Monte Carlo simulations to check the tabulated gamma-ray production data. A quantitative approach to subtract the scattered neutron background is also reported.

Irradiation of 4''x4'' NaI(Tl) detector by the 14 MeV neutrons.

Within the EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) project, a new Tagged Neutron Inspection System (TNIS) has been developed and installed in the Port of Rijeka in Croatia. The system was based on the examination of sea containers with the 14 MeV neutron beam. During the operation the characteristic gamma rays were produced and measured by several 5''x5''x10'' NaI(Tl) detectors. During this procedure some of the detectors were exposed to an intensive neutron beam radiation. It was necessary to check for possible radiation damage of the NaI(Tl) scintillator during the gamma detector selection phase of the project. The 4''x4'' NaI(Tl) detector was exposed to 14 MeV neutrons for 20 h. From the presented results on energy resolution and activation measurements it could be concluded that there are no significant differences in energy resolution before and after the irradiation by 4.7x10(11) of 14 MeV neutrons. The only problem could be the high level of medium and long term induced activity in the energy region below 2 MeV.