High-accuracy experimental determination of photon mass attenuation coefficients of transition metals and lithium fluoride in the ultra-soft energy range.

In the field of quantitative X-ray analysis techniques, such as electron probe microanalysis, precise knowledge of fundamental parameters is crucial. Especially, the accurate determination of photon mass attenuation coefficients is essential to perform correct elemental quantification. While the widely used databases offer agreement for the hard X-ray range, significant differences arise for lower photon energies.

A benchmark for Monte Carlo simulations in gamma-ray spectrometry Part II: True coincidence summing correction factors.

The goal of this study is to provide a benchmark for the use of Monte Carlo simulation when applied to coincidence summing corrections. The examples are based on simple geometries: two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The coincidence corrective factors are computed for four radionuclides.

Radionuclide-free efficiency calibration of an HPGe detector using monochromatic photon beams calibrated with a cryogenic radiometer.

A cryogenic electrical-substitution radiometer was used for the primary calibration of monochromatic photon beams at synchrotron, which are in turn employed to determine the intrinsic efficiency of an HPGe detector between 3.5 keV and 8 keV. This allowed the determination of the thickness of the dead layer, which enabled the calculation of the efficiency up to 55 keV, where the active thickness is not determinant.

Towards a radon-in-water primary standard at LNHB.

Despite widespread radon-in-water measurements, no primary radon-in-water standards currently exist. This work aims to bridge this gap by developing a system to produce radon-in-water reference materials. The system relies on cryogenic, loss-free transfer of radon, which is standardized through defined solid angle measurements, to a radon standard in water.

Measurement of the absolute gamma-ray emission intensities from the decay of 103Pd.

Palladium-103 decays through electron capture to excited levels of Rh, and especially to the 39.748-keV metastable state. A high activity palladium chloride solution was standardized by liquid scintillation, using the Triple-to-Double Coincidence Ratio method.

Measurement of the absolute gamma-ray emission intensities from the decay of Nd.

The 2011 Decay Data Evaluation Project (DDEP) evaluation for Nd includes recommended absolute emission intensities for the two main gamma-rays at 91.105 (2) keV and 531.016 (22) keV of 0.

Activity measurements and determination of nuclear decay data of Ho in the MRTDosimetry project.

Holmium-166 is a high-energy β-emitter radionuclide (~ 1.8 MeV) with a short half-life (~26.8h) that offers great potential as an alternative to Y for the treatment of liver cancer based on radioembolization.

A benchmark for Monte Carlo simulation in gamma-ray spectrometry.

Monte Carlo (MC) simulation is widely used in gamma-ray spectrometry, however, its implementation is not always easy and can provide erroneous results. The present action provides a benchmark for several MC software for selected cases. The examples are based on simple geometries, two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions.

Improvement of the activity measurement method for solid dosimeters emitting X-rays.

Today, there is growing interest for neutrons in the intermediate energy range between 100keV and 1MeV, which are responsible for damaging materials in reactor. To improve this deficiency, we use rhodium and niobium which, through the inelastic neutron scattering reaction, leads to the formation of Rh and Nb low-energy X-emitters. This paper describes the improvements and validation made on this type of complex measurement by X spectrometry: self-attenuation, fluorescence correction, and emission intensity were poorly known previously.

Consistency of photon emission intensities for efficiency calibration of gamma-ray spectrometers in the energy range from 20keV to 80keV.

The efficiency calibration for different high-purity germanium detectors in the low-energy range was established by the conventional method, using standard radioactive sources. The peak shapes were carefully analysed taking account of natural linewidth, full-energy width at half maximum and scattering. Complementary information was obtained by Monte Carlo simulation using the PENELOPE code, after optimization of the geometrical parameters.

Residual radioactivity of treated green diamonds.

Treated green diamonds can show residual radioactivity, generally due to immersion in radium salts. We report various activity measurements on two radioactive diamonds. The activity was characterized by alpha and gamma ray spectrometry, and the radon emanation was measured by alpha counting of a frozen source.

Application of GUM Supplement 1 to uncertainty of Monte Carlo computed efficiency in gamma-ray spectrometry.

The uncertainty of quantities relevant in gamma-ray spectrometry (efficiency, transfer factor, self-attenuation FA and coincidence summing FC correction factors) is realistically evaluated by Monte Carlo propagation of the distributions characterizing the parameters on which these quantities depend. Probability density functions are constructed and summarized as recommended in the GUM Supplement 1 and compared with the values obtained using the traditional approach (GUM uncertainty framework). Special cases when this approach encounters difficulties (FC uncertainty due to the uncertainty of decay scheme parameters, effect of activity and matrix inhomogeneity on efficiency) are also discussed.

Equivalence of computer codes for calculation of coincidence summing correction factors - Part II.

The aim of this study was to check for equivalence of computer codes that are capable of performing calculations of true coincidence summing (TCS) correction factors. All calculations were performed for a set of well-defined detector parameters, sample parameters and decay scheme data. The studied geometry was a point source of (133)Ba positioned directly on the detector window of a low-energy (n-type) detector.

Correction to the recommended γ-ray emission intensity of the 255.13 keV photons in the decay of (113)Sn.

The authors provide corrected measured values of the relative γ-ray emission intensity of the 255.13keV photons from the decay of (113)Sn. Consequently, new recommended values of the evaluated relative and absolute γ-ray emission intensity of the 255.

Photon emission intensities in the decay of 108mAg and 110mAg.

This study focuses on two radioisotopes of silver, (108m)Ag and (110m)Ag, characterized by a complex decay scheme. Each isotope has two disintegration modes, the isomeric transition leading to the daughter isotope ((108)Ag and (110)Ag, respectively) with a short half-life. The radioactive solution was obtained by neutron activation on silver powder enriched in (109)Ag.

Standardization of xenon-127 and measurement of photon emission intensities.

Xenon-127 was standardized by internal gas counting using three proportional counters in a differential arrangement to eliminate edge effects. The detection efficiency of the proportional counters was calculated by considering the cascade of events following the electron capture and associated gamma transitions. Activity per unit volume was measured with 0.

Equivalence of computer codes for calculation of coincidence summing correction factors.

The aim of the study was to check for equivalence of computer codes that can perform calculations of true coincidence summing correction factors. All calculations were performed for a set of well-defined detector and sample parameters, without any reference to empirical data. For a p-type detector model the application of different codes resulted in satisfactory agreement in the calculated correction factors.

Comparison of digital signal processing modules in gamma-ray spectrometry.

Commercial digital signal-processing modules have been tested for their applicability to gamma-ray spectrometry. The tests were based on the same n-type high purity germanium detector. The spectrum quality was studied in terms of energy resolution and peak area versus shaping parameters, using a Eu-152 point source.

Validation of efficiency transfer for Marinelli geometries.

In the framework of environmental measurements by gamma-ray spectrometry, some laboratories need to characterize samples in geometries for which a calibration is not directly available. A possibility is to use an efficiency transfer code, e.g.