ABSTRACT
Neutron attenuation and reflection characteristics of three crude mineral oil samples from West Africa were determined using 37 GBq 241Am-Be source in a single set-up and compared with those of paraffin (oil) and benzene, an aromatic compound. Based on the trends of measured data which are similar to those exhibited by paraffin but different from those associated with benzene, the crude oil samples could be classified as paraffinic. The total hydrogen content and weight ratios (O+C)/H and C/H determined for the crude oil samples using the transmission and reflection techniques are not only independent of the technique but are also consistent with literature values of thermal reflection technique.
ABSTRACT
A fast and non-destructive technique based on thermal neutron reflection was used to determine total hydrogen contents in petroleum products available in Ghana. A source holder consisting of an 241Am-Be neutron source and 3He neutron probe designed for detection of liquid levels was used to measure reflection parameter as a function of hydrogen contents in liquid hydrocarbons which served as standards. The measured data were fitted to two linear equations for two different geometrical arrangements. The trend of data was found to be consistent with theoretical analysis based on neutron moderation. The calibration lines were used to determine hydrogen contents in 10 petroleum products. The results agree favourably with those obtained using different experimental set-ups with other neutron sources and probes. The technique was also used to determine the quality of diluted petrol with aviation fuel.
ABSTRACT
The variation of thermal reflection parameter with thicknesses of water and paraffin moderators was measured using an instrument consisting of 1 Ci 241Am-Be isotopic neutron source and 3He neutron detector. Based on experimental data obtained from two different source-detector-sample geometries, analytical expressions were derived for calculation of reflection parameters for various moderator thicknesses. The measured data for the two geometries exhibit saturation curves with saturation achieved at about 8 and 16 cm when sample container was placed at top and side of the source holder, respectively. By locating the source holder along the vertical axis of the sample container, measurements showed that the reflection parameter was very sensitive with the axial location and was strongly dependent on the moderator and its thickness.
