Handheld XRF analysis of gold armlets with crescent-shaped terminals from the prehistoric collection of the Hungarian National Museum

A tanulmányban a Magyar Nemzeti Múzeum Őskori Gyűjteményében található, holdsarlós végű arany karpántok kézi XRF elemösszetételi vizsgálatának eredményeit mutatjuk be. Munkánkban az új, tápióbicskei darab mellett vizsgáltuk a dunavecsei, a magyarbényei, az erdélyi (Kárász Géza gyűjtemény) és a Körös vidéki darabot is. A kézi XRF elemzés alapján megállapíthatjuk, hogy a karpántok jelentős része magas Ag (21–24 wt%) és alacsony Cu tartalommal (0,06–0,17 wt%) rendelkezik. E tárgyak típusuktól vagy lehetséges időrendi besorolásuktól függetlenül viszonylag egységes csoportot (Hartmann A3) alkotnak elemösszetételük alapján. Alacsonyabb Ag tartalommal a Körös vidéki darab (kb. 5,8 wt%) (Hartmann B) és a magyarbényei karpánt szegecsei (kb. 12,3 wt%) bírtak (Hartmann L/Q2). Eredményeink alapján a vizsgált karpántok alapanyaga a korábban, részben más módszerekkel (OES, SR XRF) vizsgált példányokhoz képest (Bellye, Pipe, Mihályfalva) alacsonyabb Ag tartalommal bír. Jelen módszer az elemzett tárgyak nyersanyaga eredetének meghatározására nem alkalmas, mindössze a nyersanyag típusát különíthetjük el, amely termésarany lehetett

The bottom of the looted cauldron. Part I.

The following study deals with a looted metal sheet artefact probably originating from the Balkan region. Our main goal is to give a preliminary technological characterization of the object by the aid of four different analytical methods (macro- and microscopic observations, Neutron and X-ray Radiography, X-ray Fluorescence Spectroscopy). Using these different techniques together allowed us to characterize this complex metal sheet object more precisely than it would have been possible by traditional archaeological methods. According to our results, it seems that the technological characters of the artefact (e.g. the manufacturing technology, decorations, repair marks) are very similar to the metal sheet cauldrons of the Late Bronze Age and Early Iron Age

Lokális hidrogéntartalom mérése roncsolásmentes neutronos módszerekkel cirkónium fűtőelemburkolatok hossztengelye mentén

Magas hőmérsékletű felhasadást és oxidációt követően roncsolásmentes neutronos vizsgálatokkal hidrogén-cirkónium elemarányt határoztunk meg E110 és E110G típusú Zr fűtőelem-burkolatok hossztengelye mentén. A neutronos képalkotással kombinált prompt-gamma neutronaktivációs analízissel mintegy 30 gamma spektrumot vettünk fel az egyes burkolatokon, 5 mm-es lépésekben. A CODEX-LOCA-200 és CODEX-LOCA-E4 kísérletekben a H/Zr profilok mindkét típusú burkolatnál három csoportra oszthatók. Az elsőben csak kisebb deformáció vagy repedés látható néhány száz ppm körüli tömegarány értékekkel. A második csoportban közepes mértékű volt a felhasadás, és az értékek széles skálán (200-1800 ppm) mozognak. A legmagasabb értékeket (6000-7000 ppm) a nagy repedéssel vagy teljes töréssel rendelkező harmadik csoportban tapasztaltuk

Integration of neutron-based elemental analysis and imaging methods and applications to cultural heritage research

The present paper describes the merits of the combined neutron-based elemental analysis and neutron imaging techniques, called prompt-gamma activation imaging - neutron tomography (PGAI-NT), and illustrates its application to cultural heritage science with relevant case studies. The approach is proven to be best applicable to samples with corroded/layered/gilded/painted/coated structures where the surface weighted response would bias the analysis results obtained with simpler, more widespread, but less representative techniques (such as Xray fluorescence spectroscopy or laser-ablation ICP-MS), as well as to answer questions related to the inner composition of a sealed objec

High-energy detector calibration data for k(0)-neutron activation analysis

In k(0)-neutron activation analysis, HPGe detectors have to be calibrated up to about 3.1 MeV, in order to properly determine the Na, Ca and S content of analytes. Commercial radioactive sources cover the energy range only up to 2.2 MeV, but with activation in the reactor, additional high-energy gamma emitter radionuclides (Ga-72, Mn-56, In-116 and Na-24) can be produced. At a prompt-gamma activation analysis station, where the calibration is available up to 12 MeV, we derived accurate gamma-ray energies and relative intensities for these radionuclides and subsequently used them for broad energy-range efficiency and nonlinearity calibration of NAA detectors as well as a low-level counting station

Bimetallic Ag–Au/SiO2 catalysts: Formation, structure and synergistic activity in glucose oxidation

SiO2 supported Ag–Au bimetallic catalysts were prepared by sol adsorption method with 10/90, 20/80, 33/67, and 50/50 Ag/Au molar ratios. Reduction of HAuCl4 in Ag sol resulted in alloyed Ag–Au colloid particles and that structure remained after calcination and reduction treatment. The alloy structure of the catalysts was confirmed by UV–visible spectroscopy and high resolution transmission electron microscopy. The Au–Ag bimetallic effect and its dependence on the Ag/Au molar ratio was studied in glucose oxidation where synergistic activity increase was observed compared to the Au/SiO2 reference sample in the case of the bimetallic samples with less than Ag/Au = 50/50 molar ratio. The Ag/SiO2 was inactive at the same conditions. The Ag/Au surface atomic ratios – calculated by X-ray photoelectron spectroscopy (XPS) – were slightly higher than in the bulk—determined by prompt gamma activation analysis (PGAA). The higher activity of the bimetallic samples is suggested to be caused by the improved O2 activating ability provided by Ag sites. The further increase of Ag loading above the optimal concentration may dilute or cover the Au to such an extent that the number of gold ensembles necessary for glucose activation decreases deteriorating the activity

Use of 3D mesh geometries and additive manufacturing in neutron beam experiments

PGAI-NT, a neutron-based element composition and structure analysis method, is well applicable to the non-destructive characterization of valuable artefacts, paleontological, bulk geological samples or to industrial reverse engineering. To set up the measurement geometry and scanning positions for items with unconstrained shapes, sizes, and matrices, accurate knowledge of the object’s geometry is a must. We applied portable structured-light 3D optical scanning or segmented neutron/X-ray tomography data to produce 3D meshes of the complex samples. Subsequently, 3D printing was used to fabricate detailed replicas of museum objects, as well as their gentle ad hoc sample holders, or produce custom parts of the Budapest PGAA instrument

Benchmarking PGAA, in-beam NAA, reactor-NAA and handheld XRF spectrometry for the element analysis of archeological bronzes

Novel detection strategies were developed to improve the PGAA methodology in the analysis of bronze and brass objects. Instrumental neutron activation analysis and X-ray fluorescence were also involved in this study for comparison. The approach was tested on a set of IRMM-certified copper alloys. Reference values for the concentrations of four major additive components (As, Zn, Sn, and Pb) were compared with the results obtained by the involved methods. The bias observed between the reference Sn values and the initial PGAA results was successfully addressed by considering the interference of this line with low intensity copper prompt gamma peaks. In this report results are presented, and the analytical merits are compared