The determination of241Pu by liquid scintillation spectrometry using the Packard 2250CA

Autor: R. Anderson, G. T. Cook
Rok vydání: 1991
Předmět:
Zdroj: Journal of Radioanalytical and Nuclear Chemistry Letters. 154:319-330
ISSN: 1588-2780
0236-5731
DOI: 10.1007/bf02165488
Popis: The results of this study indicate that in terms of efficiency, the Packard 2250Ca liquid scintillation spectrometer is sensitive to the scintillation cocktail employed for241Pu analysis, particularly when the burst counting circuit is enabled. Cocktails exhibiting low t-SIE values should be avoided since quenching has a critical influence on such a low energy β− emitter. This effect would be independent of burst circuitry use. Cocktails which include naphthalene type derivatives such as the alkylnaphthalene solvent employed in Optiphase HiSafe 3 and Ultima Gold should be avoided since the broad pulse shapes produced are incompatible with the burst counting circuit which distinguishes background events from true β− events by means of pulse shape/duration analysis. Efficiency is also sensitive to the concentration of bis-MSB employed in conjunction with the primary fluor. Enhancements in efficiency are observed with appropriate concentrations. These results are in line with previous work with14C and are postulated as being a consequence of sharpening prompt pulse widths or suppression of afterpulsing. It is recommended that Instafluor should be used to maximize response, or a cocktail such as butyl-PBD/bis-MSB in pseudocumene at rates of 6 and 1.5 mg ml−1, respectively, where a lower vapor pressure solvent is particularly required.
Databáze: OpenAIRE
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