Measurement of absolute K X-ray emission intensities in the decay of Rh.

A new experiment was designed to measure the photon emission intensities in the decay of Rh. The rhodium samples were activated in the ISIS experimental nuclear reactor at CEA Saclay. The procedure includes an absolute activity measurement by liquid scintillation counting using the Triple-to-Double Coincidence Ratio method, followed by X-ray spectrometry using a high-purity germanium detector to determine the photon emission intensities.

Diffusion lengths and partition coefficients of Xe and Kr in Makrofol N and Makrofol DE polycarbonates.

This work presents the results of an experimental study of the Makrofol N and Makrofol DE polycarbonate foils absorption properties of Kr and Xe. The diffusion lengths of Kr and Xe in both types of foils are determined. The partition coefficients of Kr from air and water and that of Xe from air in Makrofol N are determined.

Determination of (222)Rn absorption properties of polycarbonate foils by liquid scintillation counting. Application to (222)Rn measurements.

This work demonstrates that a Liquid Scintillation Counting (LSC) technique using a Triple to Double Coincidence Ratio counter with extending dead-time is very appropriate for the accurate measurement of (222)Rn activity absorbed in thin polycarbonate foils. It is demonstrated that using a toluene-based LS cocktail, which dissolves polycarbonates, the (222)Rn activity absorbed in thin Makrofol N foil can be determined with a relative standard uncertainty of about 0.7%.

Experimental study of the influence of the counter and scintillator on the universal curves in the cross-efficiency method in LSC.

The cross-efficiency method in LSC is one of the approaches proposed for the extension of the Système International de Référence (SIR) to radionuclides emitting no gamma radiation. This method is based on a so-called "universal cross-efficiency curve", establishing a relationship between the detection efficiency of the radionuclide to be measured and the detection efficiency of a suitable tracer. This paper reports a study at LNHB on the influence of the scintillator and of the LS counter on the cross-efficiency curves.

Measurement of the French national tritiated-water standard by helium-3 mass spectrometry.

The (3)He ingrowth technique is based on the detection of the tritium radioactive daughter, (3)He, by mass spectrometry. Over the last three decades it has been used extensively in oceanography and groundwater studies for measurements of very low to ultra-low levels of tritium. To compare it with the best available methods of radioactive counting, we applied this method to measure the massic activity of a tritiated-water primary standard prepared by the French Laboratoire National Henri Becquerel (LNHB).