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  • Author or Editor: G. Keömley x
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Abstract  

Neutron activation analysis was used for provenance studies of ceramics from the early middle ages (avar period). 14 trace elements and Fe were determined by multiisotope comparator method. Computerized mathematical statistical methods (cluster-, and similarity analysis) were used for grouping the samples according to the similarity of their trace element distributions.

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Abstract  

The possible extension of the comparator technique of reactor neutron activation analysis into the field of epithermal neutron activation has been investigated. Ruthenium was used for multi-isotopic comparator. Experiments show that conversion of the so-called reference k-factors—determined by irradiation with reactor neutrons—into kepi-factors usable at activation under cadmium filter, can be evaluated with fair accuracy. Sources and extent of errors and their contribution to the final error of analysis are discussed.

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Abstract  

A semi-automated instrumental gamma-spectrometric measuring system with a sample changer has been developed for determination of the radioactive fission products coming from different parts of the primary coolant circuit. The measuring geometry assures higher sensitivities under normal operation conditions and lower ones for significant fuel cladding failures. The minimal detection limits are in the range of some ten Bq/l.

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Abstract  

Twelve zircon samples representing different genetic types from Australia, China, Egypt, Hungary, Korea and Nigeria were examined using the neutron activation techniques. The study of the trace elements encountered in zircons, especially Zr/Hf ratios, shed the light on the type of zircon minerals as well as the mother rock from which zircons wrre separated. Furthermore, the effect of the secondary processes on zircons and their host rocks were also studied.

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Abstract  

The possibility of using characteristic X-ray from radioactive products of reactor activation was investigated with particular emphasis on /n,/, /n,n/, /n,2n/, /n,p/ and /n,/ products with long half lives. The characteristic X-rays emitted are a result of electron capture or internal conversion processes during isomeric transition. First of all the sensitivity and detection limits were investigated.

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Abstract  

The possibility of applications of characteristic X-rays from radioactive products of reactor neutron activation was investigated with particular emphasis on (n, ), n, n), (n, 2n), (n, p) and (n, ) products with long half-lives. The sensitivity and detection limits of silver, cerium, gadolinium, selenium, cadmium and europium have been investigated. The elements were studied both in a pure and in a matrix form, in both cases the samples were diluted with graphite (90%) to minimize matrix effects (absorption and enhancement).

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Abstract  

A simple and effective method has been developed for the determination of the transuranium isotopes in primary coolant samples of WWER-440 type reactors. Membrane filters containing undissolved particles from about one liter coolant were destroyed by mineral acids, then americium-curium isotopes and neptunium-plutonium isotopes were coprecipitated sequentially with NdF3 based on their different redox behavior. Alpha-spectra were determined by silicon semiconductor detectors connected to multichannel analyzers. Activity ratios measured in a reactor unit with a failed fuel element were compared with calculated values of the same type of reactor under similar conditions. Parameters of the defective fuel (burnup, original enrichment) could be estimated.

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