A method for simultaneous determination of uranium and thorium based on the deviation of their fission cross-section curves has been developed. Using a D-T neutron generator two different neutron spectra were produced with and without moderator around the target. The detection limits were found to be 0.044 mg and 0.25 mg in the presence of a moderator, while for fast neutrons 0.017 mg and 0.037 mg for uranium and thorium, respectively.
The perturbation of thermal neutron flux has been determined by an experimental method for absorbing samples using252Cf neutron source. The distribution of thermal neutron flux was measured in dysprosium and gold foils of various thicknesses.
An empirical analytical formula is given for the description of flux distribution in the foils.
Applicability of a small neutron generator and a dual rectangular tube sample transfer system for analyses of U and Th using delayed fission neutron technique has been investigated. A way of optimizing the timing parameters is reported. At a fast neutron flux of 108 n.cm–2s–1, 0.02 w% U can be determined. For thorium determination this method is less sensitive. The Cd difference technique can be used for the simultaneous determination of U and Th but it has lower sensitivity.
Authors:J. Csikai, S. Al-Jobori, Cs. Buczkó, and S. Szegedi
The concentrations of O, Na, Cl, V, Mn and Ni in crude oils of different origins were determined, using sampling (SNAA) and
on-stream (ONAA) activation analyses. Samples were irradiated with thermal and fast neutrons produced by a 0.3 mg252Cf source and a 14 MeV generator. The H-content and the C/H atomic ratio have been determined by thermal neutron reflection
method using an 18 GBq Pu−Be source.
Authors:S. Szegedi, M. Váradi, Cs. Buczkó, M. Várnagy, and T. Sztaricskai
Neutron transmission method has been used for the determination of boron in borosilicate glasses. The method is sensitive and rapid to control the spatial homogeneities of glass-product in the melting furnace.
Authors:Cs. Buczkó, S. Mukherjee, Z. Dezső, M. Hegedüs, and M. Várady
The determination of the titanium content of bauxite samples of various origin was studied by thermal neutron activation and
X-ray analysis. A252Cf-fission neutron source and a Ge(Li) detector as well as a3H exciting source and a Si(Li) detector were used in the investigations. Within equal measuring times and with a sample weight
of 8 g the sensitivity of the activation method is 0.35 w% Ti with an absolute statistical error less than 10%, while that
of the X-ray method is 0.06 w% Ti and the absolute statistical error does not exceed 5%.