PIGE analysis and profiling of aluminium

In this work we present an alternative method for PIGE analysis of aluminium in thick samples. This method is based on the ERYA - emitted radiation yield analysis - code, which integrates the nuclear reaction excitation function along the depth of the sample. For this purpose, the excitations functions of the ²⁷Al(p,p′γ_1,2)²⁷Al reaction (with gamma-ray energies of 844 and 1014 keV) were employed. Calculated gamma-ray yields were compared, at several proton energy values, with experimental yields for thick samples made of inorganic compounds containing aluminium. The agreement is better than 5%.The 1684 keV resonance of the same reaction, with a natural width of 100 eV, was used to profile samples of Ti implanted with several doses of Al. We show that this resonance, stronger than the 992 keV resonance of the ²⁷Al(p,γ)²⁸Si usually employed for aluminium profiling, leads to similar depth resolution in shorter collection time.     

Golden glazes analysis by PIGE and PIXE techniques

We present the analysis performed on the chemical composition of two golden glazes available in the market using the PIGE and PIXE techniques at the ITN ion beam laboratory. The analysis of the light elements was performed using the Emitted Radiation Yield Analysis (ERYA) code, a standard-free method for PIGE analysis on thick samples. The results were compared to those obtained on an old glaze. Consistently high concentrations of lead and sodium were found in all analyzed golden glazes. The analysis of the samples pointed to Mo and Co as the specific elements responsible of the gold colour at the desired temperature, and allowed Portuguese ceramists to produce a golden glaze at 997 °C. Optical reflection spectra of the glazes are given, showing that the produced glaze has a spectrum similar to the old glaze. Also, in order to help the ceramists, the unknown compositions of four different types of frits (one of the components of glazes) were analysed.     

PIXE and PIGE techniques for the analysis of Antarctic ice dust and continental sediments

An analytical procedure has been implemented in this work for an accurate geochemical characterization and quantitative analysis of the fine dust (particles diameter < 5 μm) trapped in Antarctic ice cores and the fine fraction of potential source areas (PSA) sediments by size selection, filtering and PIXE-PIGE combined measurements. The underestimation of concentrations of the lighter elements, like Na, Mg, Al and Si, due to X-ray self-absorption inside each individual aerosol particle, was also evaluated and the analytical overall accuracy tested by means of measurements performed on size selected certified mineral standards.     

The sensitivity of the PIGE analytical technique

The aim of this work is to provide a basis for the estimation of fluorine and lithium contributions to the background of gamma-ray spectra and of their influence on PIGE (Proton-Induced Gamma-Ray Emission) detection limits of lithium, boron, fluorine and sodium. Results for yields and background contributions of lithium and fluorine were obtained from measurements using samples of known composition. Detection limits were determined by extrapolation of those measurements and by calculations based on the inferred background values. Yields were converted in concentrations using the ERYA (Emitted Radiation Yield Analysis) code. This code divides the sample in sublayers parallel to its surface for the integration of the partial gamma-ray yields along the depth of the target.     

Combined PIXE/PIGE and IBIL with external beam applied to the analysis of Merovingian glass beads

New improvements on our archaeometry line at the cyclotron of the Institute of Nuclear and Atomic Physics and of Spectrometry of the University of Liège have allowed the use of PIXE/PIGE and IBIL in-air for the analysis of cultural heritage objects. The extraction is performed through a 100 nm thick Si₃N₄ window. The detection set-up consists now of two X-ray and one γ-ray detectors, together with a fiber optic UV–visible spectrometer. This set-up has already been tested for the analysis of modern corundum [1] and is now adapted to the analysis of archaeological artefacts. In this work, we have used it to analyse 216 out of the 5000 Merovingian glass beads that come from the necropolis of Bossut-Gottechain (Belgium), one of the most important ever found in Belgium.The IBA analyses confirmed the typological division of different beads groups through chemical composition that gives us new insights on fabrication techniques of glass matrices and colorants.     

Can aluminium or magnesium be a surrogate for beryllium: A critical investigation of their chemistry

The use of beryllium is still an existing question according to the studies concerning the plasma–wall interactions which are expected to occur in ITER. Prediction of erosion and co-deposition processes for ITER is necessary for the design and the material choice of the first wall. In the current configuration, it is expected that co-deposited layers containing Be, tungsten and possibly carbon will be formed. However, the toxicity of Be limits its use in many experimental facilities around the world. Using aluminium or magnesium as Be replacements in laboratory experiments would solve this problem of toxicity and handling of Be mixed materials. A critical question which automatically arises is the relevance to use Al or Mg regarding the physical and chemical properties of both elements in comparison to the co-deposited layers expected in ITER. This work provides a review of the chemical and physical properties of Al and Mg, in the respect of comparing these properties to those of Be. Thanks to the similarity of its electronegativity to Be, Al can successfully resemble Be in terms of formation of compounds, especially the oxides and possibly the hydrides. However, due to the difference in the nature of the bonding, Mg cannot be a replacement for a possible hydride deposit formation.     

Aging of beryllium

A survey of studies devoted to the possibility of increasing the plasticity of technical-purity beryllium within the temperature region 400–600°C is given. It is shown that the heat treatment of beryllium at 600–800°C leads to the deposition of the superfluous phases from the supersaturated solution. This is accompanied by a substantial change in the properties of the metal, in particular, the plastic and strength characteristics, hardness, creep, and electric resistance. The results of metallographic, electron microscopic, electron diffraction, x-ray diffraction, and other investigations of the microstructure of beryllium in various states are cited. The mechanism of the aging of beryllium is described on the basis of the available data, and practical conclusions are drawn on the possibilities of increasing the plasticity of beryllium at high temperatures.Translated from Atomnaya Énergiya, Vol. 19, No. 2, pp. 144–153, August, 1965     

The credit analysis of recycling beryllium and uranium in BeO-UO2 nuclear fuel

This study quantifies the credits of beryllium and uranium which are used as the raw materials for BeO-UO₂ nuclear fuel by analyzing the influence of their credits on the nuclear fuel cycle cost was analyzed, where the credit was defined as the value of raw materials recovered from spent fuel and the raw materials that were re-cycled. The credits of beryllium and uranium at 60 MWD/kg burn-up were –0.22 Mills/kWh and –0.14 Mills/kWh, respectively. These findings were based on the assumption that the optimal mixing proportion of beryllium in the BeO-UO₂ nuclear fuel is 4.8 wt%. In sum, the present study verified that the credits of beryllium and uranium in relation to BeO-UO₂ nuclear fuel are significant cost drivers in the cost of the nuclear fuel cycle and in estimating the nuclear fuel cycle of the reprocessing option for spent nuclear fuels.     

Reaction between beryllium and uranium monocarbide

The reaction between hot-pressed beryllium and arcmelted uranium monocarbide has been studied in the temperature range 700 to 1000° C using A-B type diffusion couples. The carbide used was of two compositions — 4.8 and 5.1 wt % C. Reaction occurred throughout the temperature range studied, resulting in a layer of UBe₁₃ with a uniformly dispersed precipitate which could not be identified. The reaction was found to be controlled by the diffusion of beryllium in UBe₁₃ with reaction occurring at the UBe₁₃-UC interface. An activation energy of 33 000 cal/mole was determined for the process.     

DETERMINATION OF ~(13)C IN BREATH SAMPLE BY PIGE

This paper discusses a novel application of PIGE for the determination of 13C in breath sample. Samples of human breath, urea, glucose, benzamide, barium carbonate were analyzed against tank CO2 and graphite standard. An accuracy check of the 13C determination (with reference to mass spectrometric "True" results) gave a relative error of only- 0.4% for PIGE. The performance of different standard in this determination was assessed. Relative standard deviation for the determination of 13C isotopic abundance in breath samples were <20%. Then, if a 25% change is conservatively assumed observable in 13C abundance, an increase in 13C percent isotopic abundance from the natural 1.11% (average) to only 1.39% may be detected.     

Be in commercial beryllium

¹⁰Be has been observed at a level of about 10⁻¹⁴ in four commercially available beryllium compounds. The possibility that this ¹⁰Be arises from cross-talk in the ion source has been eliminated. On the other hand, beryllium oxide extracted from beryl crystals found at a depth of 30–40 feet in a lithium mine in South Dakota shows no indication of containing ¹⁰Be. An upper limit on its ¹⁰Be:⁹Be ratio is 1.7 × 10⁻¹⁵ at the 95% confidence level.