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This paper presents the first determination of the improvement in beam divergence when including the ANET Compact Neutron Collimator on an existing thermal neutron beam, obtained with a measuring campaign at the LENA Mark-II TRIGA reactor in Pavia. This novel collimator consists of a sequence of collimating and absorbing channels organised in a chessboard-like geometry. It has a scalable structure both in length and in the field of view. It is characterized by an elevated collimation power within a limited length. Its scalability and compactness are added values with respect to traditional collimating system. The prototype tested in this article is composed of 4 concatenated stages, each 100 mm long, with a channel width of 2.5 mm, delivering a nominal L/D factor of 160. This measuring campaign illustrates the use of the ANET collimator and its potential application in ne

A synergic combination of neutron techniques was applied to characterize non-invasively the laminated structure of a set of ancient katana, part of the East Asian Collection of the Museum of Applied Arts and Sciences (MAAS) in Sydney. Neutron tomography, diffraction, residual stress and Bragg-edge transmission analyses were undertaken on samples of well-known origin, time period and authorship to create a reference database on the main manufacturing methods developed by Japanese swordsmiths. In the attempt to attributemumei(no-signature) blades basing on a scientific analytical method rather than a stylistic analysis, data from the reference samples were benchmarked against the results obtained from the unknown blade to identify differences and commonalities in the production process.

Amongst the more than 18 different forms of water ice, only the common hexagonal phase and the cubic phase are present in nature on Earth. Nonetheless, it is now widely recognized that all samples of ‘cubic ice’ discovered so far do not have a fully cubic crystal structure but instead are stacking-disordered forms of ice I (namely, ice Isd), which contain both hexagonal and cubic stacking sequences of hydrogen-bonded water molecules. Here, we describe a method to obtain large quantities of cubic ice Ic with high structural purity. Cubic ice Ic is formed by heating a powder of D2O ice XVII obtained from annealing of pristine C0 hydrate samples under dynamic vacuum. Neutron diffraction experiments performed on two different instruments and Raman spectroscopy measurements confirm the structural purity of the cubic ice, Ic. These findings contribute to a better understanding of ice I polymorphism and the existence of the two natural ice forms. Structurally pure cubic ice Ic is obtained from the controlled heating of D2O ice XVII.

Kurzfassung Die Computer-gestutzte Laminografie (CL) wurde als komplementare Methode zur Computertomografie fur die dreidimensionale Bildgebung von lateral ausgedehnten Objekten entwickelt. Ursprun...

In this work the concept of a novel slow neutron collimator and the way to operate it are presented. The idea is based on the possibility to decouple the device field-of-view from its collimation power. A multi-channel geometry is proposed consisting of a chess-board structure where highly neutron-absorbing channels are alternated to air channels. A borated polymer was purposely developed to produce the attenuating components in the form of square-sectioned long rods. A scalable structure consisting of multiple collimation sectors can be arranged. The geometrical parameter LD, corresponding to the ratio between the length of a channel and its width, defines the collimation power. Several sectors can be arranged one after the other to reach relevant collimation powers. Each sector, 100 mm long, is composed by several channels with D = 2.5 mm corresponding to an L/D coefficient of 40. The target field of view is 50x50 mm2. This novel collimator, developed inside the INFN-ANET collaboration, due to its intrinsic compactness, will be of great importance to enhance the neutron imaging capability of small to medium-size neutron sources., 8 pages, 5 figures, accepted for publication to JINST

Detectors are a key feature of the contemporary scientific approach to cultural heritage (CH), both for diagnostics and conservation. INFN-CHNet is the network of the Italian National Institute of Nuclear Physics that develops and applies new instrumentation for the study of CH. This process results in both optimized traditional state-of-the-art and highly innovative detection setups for spectrometric techniques. Examples of the former are X-rays, gamma-rays, visible-light and particles spectrometers tailored for CH applications, with optimized performances, reliability, weight, transportability, cost, absorbed power, and complementarity with other techniques. Regarding the latter, examples are ARDESIA, the array of detectors at the DAΦNE-Light facility, the MAXRS detection setup at the Riken-RAL muon beamline and the imaging facilities at the LENA Laboratory. Paths for next-generation instruments have been suggested, as in the case of the X-ray Superconductive Detectors and X-ray Microcalorimeter Spectrometers, allowing astonishing improvement in energy resolution. Many issues in CH can now be addressed thanks to scientific techniques exploiting the existing detectors, while many others are still to be addressed and require the development of new approaches and detectors.

In this paper, we present the results of the archaeometric analysis performed on a nuragic bronze statuette, representing a boat model decorated with zoomorphic figurines, made in Sardinia during the early Iron Age. The bronze boat model was found in the Etruscan tomb of the Duce located in Vetulonia (Italy) and dated no later than the second half of the seventh century bc. The Vetulonia boat model represents an extraordinary example of this type of objects, exhibiting a high level of complexity from the manufacturing point of view and an unusual choice of the subjects represented by the figurines. The study was performed by means of Time of Flight Neutron Diffraction, a non-destructive method able to give us quantitative information on phase composition and microstructure.

The Monte Sa Idda type swords belong to a well characterized typological class, whose origin has long been debated and seems to coincide with the Iberian Peninsula. The name comes from the site of the first discovery of a hoard containing this type of swords, among other bronze artefacts, namely Monte Sa Idda, Decimoputzu-Cagliari, Italy. The swords were produced through fusion inside a casting mould. Such kind of casting mould has not been found in Sardinia, and this may suggests that finished objects were either imported or made using clay or sand casting mould. Moreover, the discovery of these types of sword, in hoards and in votive deposits, raises the problem of their functional use. It is unknown if the blades were intended to be used as weapons, and therefore subjected to cold working necessary for thinning and sharpening of the blade, or as ceremonial objects. In order to answer to these questions, a neutron diffraction experiment was performed on three swords belonging to the Monte Sa Idda type. The results obtained are presented and discussed in the paper.

In this work we present the analysis of the micro-structural features of ancient Indian blades carried out by neutron tomography and neutron diffraction. The results provide a clear identification of the different types of steel used to produce such weapons. Among them, only a small proportion of the large number of swords produced in India were made of hypereutectoid patterned steel, namely wootz , also (misleadingly) known as “Damascus steel”. The results permitted us to determine the spatial distribution of the iron and steel components inside the swords and the size and orientation of the microstructure of the ferrite and cementite grains in the wootz steel. These results are an important step forward towards the comprehension of the metal preparation and the forging procedure to produce swords made of wootz steel. These results are further proof of the validity of the use of neutron techniques as a non-destructive scientific analytical tool for quantitative authentication and characterization of ancient metal artefacts.

Experimental tests are presented that assess the cross-talk level among three scintillation detectors used as neutron counters exploiting the thermal neutron radiative capture on Cd. The measurements were done at the INES diffractometer operating at the ISIS spallation neutron source (Rutherford Appleton Laboratory, UK). These tests follow a preliminary set of measurements performed on the same instrument to study the effectiveness of this thermal neutron counting strategy in neutron diffraction measurements, typically performed on INES using squashed 3He filled gas tubes. The experimental data were collected in two different geometrical configurations of the detectors and compared to results of Monte Carlo simulations, performed using the MCNP code. © 2017 Elsevier Ltd

This paper presents the first determination of the spatial resolution of the ANET Compact Neutron Collimator, obtained with a measuring campaign at the LENA Mark-II TRIGA reactor in Pavia. This novel collimator consists of a sequence of collimating and absorbing channels organised in a chessboard-like geometry. It has a scalable structure both in length and in the field of view. It is characterized by an elevated collimation power within a limited length. Its scalability and compactness are added values with respect to traditional collimating system. The prototype tested in this article is composed of 4 concatenated stages, each 100mm long, with a channel width of 2.5mm, delivering a nominal L/D factor of 160. This measuring campaign illustrates the use of the ANET collimator and its potential application in neutron imaging for facilities with small or medium size neutron sources., Comment: 9 pages, 8 figures, prepared for submission to JINST

Archeological artifacts can be analyzed after neutron irradiation at the pulsed ISIS neutron and muon source, UK, using a newly installed high purity germanium gamma ray spectrometer to perform neutron activation analysis. In this work, the details of the measurement methods and data analysis are presented. In particular, it is explained how Monte Carlo calculations are necessary to evaluate the detection efficiency, taking into account self-shielding effects. The results for two certified bronze standards are presented. The good agreement between expected and measured compositions is promising for the use of this technique for archeological artifacts where the elemental concentration is often unknown. As an example, the analysis of a Chinese sword from the first or second century BC is presented.

In this research, we performed radiographic experiments exploiting polychromatic phase-contrast imaging, a method for contrast enhancement in transmitted neutron beams by measuring a sample made with a homogeneous material but exhibiting a different microstructure induced by mechanical actions. We were able to reveal the armourers’ marks now obscured by polishing that are present in these examples of medieval armour.

Vikings (800–1050 CE) are famous for being fearsome seafarers and their weapons represented an indispensable tool in their plundering raids. Sword from the Viking age often showed pattern-welding, made by welding together thin strips of iron and steel that were twisted and forged in various ways, producing a decorative pattern on the surface. In this work we present a neutron diffraction study of three swords from the Viking age belonging to the National Museum of Denmark. This non-invasive approach was used to allow us to characterise the blades in terms of composition and manufacturing processes involved. The study shows how the effects of past conservation treatments can either help or obstruct the extraction of archaeological information.

This paper focuses on recent archaeometric investigations conducted with the neutron imaging station DINGO at ANSTO. The synergic application of non-invasive scientific analytical methods is becoming a common practice in archaeometry and conservation science. Neutron tomography is playing a significant role in expanding the technical limits and investigation capabilities of traditional analytical methods. We discuss advantages and limitations of the technique through the discussion of results obtained from the investigation of artefacts produced by different ancient cultures.

A large amount of iron and steel artifacts produced in the central European area between 2nd and 14th Centuries is constituted by pattern welded iron-phosphoric iron and steel components. Phosphoric iron is a substitutional alloy, which is obtained by using iron ore from swamps in which decomposition of dead organisms enriches the iron rich soil with phosphorous. The identification of phosphoric iron alloy in ancient artifacts is important for determining their place of origin, production procedure and technological characteristics. A well-established technique for investigating the bulk structure of ancient metallographic artifacts is neutron tomography, using cold neutrons. It provides image-data capable of enhancing differences between phosphorous rich iron and the standard iron areas. However, neutron imaging is costly and complex to implement. Therefore, the exploration of new techniques capable of providing additional data on the nature of alloys would be highly needed. A pilot study addressed to test the applicability of reflectance hyperspectral imaging to the investigation of ancient metallographic artifacts is presented here. So far this technique has been used for diagnostics of polychrome surfaces, but it has never been applied to investigation of metallic surfaces. Hyperspectral imaging in the VIS-NIR range (400-1700 nm) was applied on replicas of a historical object from the archaeological site of Kobilic (Croatia). The same replicas were analyzed also using neutron tomography. Hyperspectral data were elaborated to map the distribution of the different phases on the surface. The comparison of the hyperspectral data with the neutron tomography data-images provided prominent similarities. These preliminary results encourage further investigations on merging these two imaging techniques for novel applications on archeo-metallurgy.

Deuterated ice XVII, a metastable solid water polymorph, was filled with Ne and O2 at p ≈ 100 kPa and studied by in situ neutron diffraction (ILL, France). Powder patterns were collected in the ranges of 20-50 K (Ne) and 4.6-90 K (O2). Rietveld refinement and difference Fourier techniques showed that the gas molecules were located inside the hexagonal channels of the host ice. Both Ne atoms and O2 molecules are arranged in a spiral-like configuration off the channel axis, preserving the P6122 symmetry of the host in the case of Ne, but reducing it to P61 in O2. A larger Ne absorption compared to Ne-filled ice II is observed, which is consistent with longer host-guest contacts producing smaller hydrophobic repulsion. In O2-filled ice XVII, instead, short O-D distances (2.37 Å) have attractive character and stabilize the structure.

A mapping measurement using pulsed neutron diffraction with time-of-flight method is performed on a full-shape Japanese sword made in Keicho era (1596-1615). The obtained diffraction patterns are analyzed by the Rietveld refinement and a line profile analysis. The constituent phases in the area closer to the back of the blade (ridge) are found to be ferrite and cementite, composing pearlite, while the area close to the edge is composed by martensite and austenite. The distributions of constituent phases are well explained with the distributions of dislocation density and crystallite size. The residual macroscopic stresses are estimated from the obtained lattice parameters of constituent phases. The distributions of residual macroscopic stresses in the width and thickness directions are small. The stress in the longitudinal direction is compressive at the ridge side, turns to quite large tensile at the middle part of width, then drastically decreases to be quite large compressive at the edge side of about -650 MPa. The carbon content in the area closer to the ridge side is high, about 0.9 mass%, expecting that the Japanese sword used in this study was created by the technique of maru, i.e., the use of a single type of high-carbon steel for the whole volume.

Neutron techniques are successfully employed as investigation tools in the field of cultural heritage. Thanks to their interaction processes with matter, neutrons are an effective noninvasive and nondestructive means for phase, internal morphology, elemental and isotopic characterization, and offer unique capabilities. Neutrons are a penetrating probe for bulk analysis of heavy elements such as metals, ceramics, and stones where object thickness can even be in the order of many centimeters. This chapter focuses on the application of neutron diffraction neutron activation analysis prompt gamma activation analysis, and neutron resonance capture analysis and their application in cultural heritage studies.

Deuterated ice XVII, a metastable solid water polymorph, was filled with Ne and O-2 at p approximate to 100 kPa and studied by in situ neutron diffraction (ILL, France). Powder patterns were collected in the ranges of 20-50 K (Ne) and 4.6-90 K (O-2). Rietveld refinement and difference Fourier techniques showed that the gas molecules were located inside the hexagonal channels of the host ice. Both Ne atoms and O-2 molecules are arranged in a spiral-like configuration off the channel axis, preserving the P6(1)22 symmetry of the host in the case of Ne, but reducing it to P6(1) in O-2. A larger Ne absorption compared to Ne-filled ice II is observed, which is consistent with longer host-guest contacts producing smaller hydrophobic repulsion. In O-2-filled ice XVII, instead, short O-D distances (2.37 angstrom) have attractive character and stabilize the structure.

The present work, performed by means of ex-situ neutron diffraction measurements and combined with complementary Raman data, reports the first structural characterization of the recovered hydrogen hydrate during the transformation from the C0 phase to ice XVII. The measurement of the position of the Bragg reflections in the neutron data allows to obtain the behaviour of the lattice parameters for the C0 filled ice as a function of temperature during hydrogen release. From this analysis, we demonstrate the irreversibility of the structural changes passing from the pristine filled hydrate to the empty one, i.e. ice XVII. Meanwhile, we observe also the release of the spurious nitrogen molecules previously absorbed by the hydrate crystal when recovered at low temperature and ambient pressure. A significant release of guest molecules starts around 60 K, reaching the complete evacuation of the water structure above 100 K.

The silver coinage of Celtic tribes settled in northern Italy (IV–I century B.C.) is a topic characterized by several issues, such as chronology, attributions and relationships between emissions produced in different periods. In order to provide numismatists with new data, several specimens, belonging to different typologies, have been analysed with neutron diffraction technique to overcome surface alteration and to provide bulky compositional and structural information of the coins. Measurements performed with the INES diffractometer at the ISIS facility provided essential data for numismatics research. A clear silver debasement occurring between the first and latter emissions has been traced, due to inflation processes which can be related with the increasing power of Roman Republic in the Cisalpine region. Moreover, compositional data enabled for the first time to identify internal evolutions inside typologies defined by numismatists. The silver loss has also been used to establish a relative chronology between different emissions. Other parameters such as texture index, residual strains and grain dimensions have been useful to understand technical aspects of minting procedures during Iron Age.

Iulia Concordia is an important Roman settlement known for the production of iron objects and weapons during the Roman Empire. A huge number of well-preserved styli were found in the bed of the main channel of the city. In order to shed light on the production processes used by Roman for stylus manufacturing and the conservation state of the finds, a neutron tomography analysis was performed on NEUTRA beamline in Switzerland. SEM-EDS analyses were performed on few selected objects in order to identify the composition of metal decorations. Here, we present results from our investigation conducted on 91 styli, disclosing, in a non-invasive way, the morphological characterization related to the ancient Roman working techniques.

The measurement of the fineness of debased ancient silver coins has proven to be a very difficult issue, which has been studied for a long time. In this paper, this subject is analysed, and the various consequences of the silver surface enrichment (SSE) are discussed exploiting the most recent investigations. A new model is proposed for the complex ob- ject that is an ancient-debased silver coin, based on the silver profiles measured on some sectioned specimens. The model is applied to a sample of 43 coins, mainly Roman victoriati, Cisalpine and Illyrian drachms (from late III to I century B.C.). The coins are investigated in two different ways: neutron diffraction (ND) and specific gravity (SG). The results of the two measurements are combined via the proposed model to provide a more complete numismatic information of the original fineness of the monetary alloy. As a result, a relation between SSE thickness and SG is derived, which, for these coinages, allows to estimate the original alloy silver content from a simple SG measurement; the same method can be used to study other debased coinages, provided that all the procedure (ND and SG) is applied

The scope of imaging has changed significantly in recent years. Apart from improving spatial resolution continuously it has moved focus from a visual inspection technique in non-destructive testing...

Neutron computed tomography relies on plain mathematical projections of the sample onto an ideal detector to reconstruct a three-dimensional model of the sample. However, several effects disturb this assumption, like buildup of afterglow on the scintillation screen, degradation of the screen during the measurement, background by neutrons scattered in the sample, and edge effects by reflection and refraction on sample edges and surfaces. Calculating a correct mathematical correction, e.g. using a point spread function, requires a lot of a priori knowledge about the sample and the detection system and cannot be given universally. This publication describes the observation of artefacts in neutron imaging and gives physical arguments for simple mathematical corrections to reduce, but not fully remove these artefacts in the reconstructed image. Often, awareness of these error sources is even more important than full removal.

Non-invasive experimental methods play an important role in the field of cultural heritage. Benefiting from the technical progress in recent years, neutron imaging has been demonstrated to complement effectively studies based on surface analysis, allowing for a non-invasive characterization of the whole three-dimensional volume. This study focuses on a kris and a kanjar, two weapons from ancient Asia, to show the potential of the combined use of X-ray and neutron imaging techniques for the characterisation of the manufacturing methods and the authentication of objects of cultural and historical interest.

Distribution, penetration depth and amount of new mineralogical phases formed after the interaction between an inorganic treatment and a matrix are key factors for the evaluation of the conservation treatment behaviour. Nowadays, the conventional analytical methodologies, such as vibrational spectroscopies, scanning electron microscopy and X-ray diffraction, provide only qualitative and spot information. Here, we report, for the first time, the proof of concept of a methodology based on neutron imaging able to achieve quantitative data useful to assess the formation of calcium oxalate in a porous carbonatic stone treated with ammonium oxalate. Starting from the neutron attenuation coefficient of Noto stone-treated specimens, the concentrations of newly formed calcium oxalate and the diffusion coefficient have been calculated for both sound and decayed substrates. These outcomes have been also used for a comparative study between different treatment modalities. Graphical abstract Horizontal slice at 300 mm depth and CaOx molar density profile by NEUTRA output.

A mapping measurement using pulsed neutron diffraction with time-of-flight method is performed on a full-shape Japanese sword made in Keicho era (1596–1615) to elucidate the manufacturing process. The obtained diffraction patterns are analyzed by the Rietveld refinement and a line profile analysis. The constituent phases in the area closer to the back of the blade (ridge) are found to be ferrite and cementite, composing pearlite, while the area close to the edge is composed by martensite and austenite. The distributions of constituent phases are well explained with the distributions of dislocation density and crystallite size. The carbon contents in the area closer to the ridge side estimated from the phase fraction of cementite and in the area closer to the edge side considered from the phase fraction of austenite are similar, 0.9–1.0 mass%, expecting that the Japanese sword used in this study was created by the technique of maru, i.e., the use of a single type of high-carbon steel for the whole volume. The residual macroscopic stresses are estimated from the obtained lattice parameters of constituent phases. The distributions of residual macroscopic stresses in the width and thickness directions are small. The stress in the longitudinal direction is compressive at the ridge side, turns to quite large tensile at the middle part of width, then drastically decreases to be quite large compressive at the edge side of about −650 MPa.

The Italian Neutron Experimental Station (INES) located at the ISIS pulsed neutron source (Didcot, United Kingdom) provides a thermal neutron beam mainly used for diffraction analysis. A neutron transmission imaging system was also developed for beam monitoring and for aligning the sample under investigation. Although the time-of-flight neutron diffraction is a consolidated technique, the neutron imaging setup is not yet completely characterized and optimized. In this paper the performance for neutron radiography and tomography at INES of two scintillator screens read out by two different commercial CCD cameras is compared in terms of linearity, signal-to-noise ratio, effective dynamic range and spatial resolution. In addition, the results of neutron radiographies and a tomography of metal alloy test structures are presented to better characterize the INES imaging capabilities of metal artifacts in the cultural heritage field. (c) 2013 Elsevier B.V. All rights reserved.

For the first time, a quick method to discriminate between undamaged, well-maintained katanas and worn artificially restored blades is presented. The peculiar hardening process that a Japanese katana undergoes results in creation of a tempered martensitic phase near the blade edge. After the temper, traditional polishing with stones is performed, which gives the sword its final look: the hardened zone exhibits matte finish, and it is separated from the shinier zone by the hamon line, which is the most characteristic feature of a katana. If the sword is worn, the martensitic phase disappears and so does the hamon line, the sword losing most of its commercial value. However, an acid bath can simulate the matte texture of an undamaged martensitic structure, making it really difficult to recognize valuable blades from worn ones. So far, no analytical approach helping in this task was available. The method we present is based on the hypothesis that traditional polishing leaves a very tiny amount of stone dust on the blade, whereas the acid bath rinses it away. The presence on the blade surface of Si (the major component of the stones used for polishing) when the hamon line is clearly visible could thus be a reasonable marker indicating that the blade is maintaining its original martensitic structure and thus is in a good conservation state. For the Si detection, X-ray fluorescence technique was chosen, which ensures non-destructivity, high sensitivity, and short measurement time with a portable instrument. Copyright © 2013 John Wiley & Sons, Ltd.

Introduction Coins are widely studied in archaeometry because they provide a lot of information on the social, economical, and technological history of the people and territories, which they are related to. In fact, they were generally struck, made of a well controlled alloy by a known mint, and sometimes they also have a date of issue. Other references can be found in ancient documents and, as been done for Roman coins, their typology, metrology, and chronology have already been well studied [1-3]. However, the lack of documentation on the minting technological processes (casting, mechanical working, heat treatment) requires chemical and metallurgical investigation to obtain a detailed description of the coinage production. Metallography is an important tool that provides useful data on the quality of the used alloy and the thermo-mechanical history of the sample, which are strongly related to the production technology. A multidisciplinary approach to the problem of these issues may solve, above all through microstructural analyses, some general questions on coin production, chronology and official/unofficial minting, opening new perspectives to the study of these materials. ... ...

We measured two-dimensional transmission spectra of pulsed neutron beams for a Japanese sword sample. Atom density, crystalline size, and preferred orientation of crystals were obtained using the RITS code. The position dependence of the atomic density is consistent with the shape of the sample. The crystalline size is very small and shows position dependence, which is understood by the unique structure of Japanese swords. The preferred orientation has strong position dependence. Our study shows the usefulness of the pulsed neutron transmission method for cultural metal artifacts.

VESPA, Vibrational Excitation Spectrometer with Pyrolytic-graphite Analysers, aims to probe molecular excitations via inelastic neutron scattering. It is a thermal high resolution inverted geometry time-of-flight instrument designed to maximise the use of the long pulse of the European Spallation Source. The wavelength frame multiplication technique was applied to provide simultaneously a broad dynamic range (about 0-500 meV) while a system of optical blind choppers allows to trade flux for energy resolution. Thanks to its high flux, VESPA will allow the investigation of dynamical and in situ experiments in physical chemistry. Here we describe the design parameters and the corresponding McStas simulations.

We present novel imaging results from a non-invasive examination of three 'pattern-welded' swords from the Viking Age belonging to the National Museum of Denmark, using white beam and energy resolved tomographies with neutrons. Pattern-welded blades are made by forge welding together thin strips of iron and steel that were twisted and joined in various ways, producing a decorative pattern on the surface. The study shed light on the inner structure of the composite material and manufacturing techniques of these admired examples of past technology, revealing some otherwise invisible details of their assembly methods, phase distribution and extent of the corrosion.

The structure of the recently identified metastable ice XVII, obtained by release of hydrogen from the C-0-structure D2O-H-2 compound (filled ice), has been accurately measured by neutron powder diffraction. The diffraction pattern is indexed with a hexagonal cell and can be refined with space group P6(1)22 so as to obtain accurate values of the oxygen and deuterium positions. The values of the lattice constants at three temperatures between 25 and 100 K are reported, and their behavior is compared with that of ice Ih. Ice XVII is a microporous solid that, if exposed to H-2 gas, may adsorb a substantial amount of it. Monitoring this effect at a constant temperature of SO K, we have observed that the two lattice constants show opposite behavior, a increases and c decreases, with the volume showing a linear increase. At temperatures higher than 130 K, the metastability of this form of microporous ice is lost and the sample transforms into ice Ih.

This work presents the non-invasive analysis, through time of flight neutron diffraction, of a unique grey metal ferrous artefact in the shape of an awl. This object was found together with other copper samples in the Selvicciola Necropolis, which includes 34 eneolithic underground tombs, dated radiometrically between halfway through the fourth millennium and the end of the third millennium BC. The sample was originally covered with mineralization products. However, its main peculiarity resided in an almost total absence of rust. The uniqueness of such a sample imposed a non-invasive approach for its analytical study. In addition, being a singular object, in that environment, its study was considered mandatory to better understand the metallurgical skills of a copper-age community in central Italy. Thermal neutron scattering techniques have provided a wealth of information about the composition, the smelting process, and the mechanical and thermal treatments applied during the manufacture of the sample. The results obtained suggest that the sample had been treated according to the typical approach used for copper alloy smelting and smithing, i.e. cold working at room temperature and annealing at [similar]700 to 800 °C.

Neutron diffraction experiments have been per-formed on laboratory-prepared samples of copper alloys to determine their microscopic phase characteristics. The aim of this experiment is to set up a database that can be used in future neutron diffraction measurements on metal samples mainly of archaeological interest.

The upgraded version of the GEM side-on thermal neutron detector was successfully tested in a neutron diffraction experiment on a reference sample using the INES diffractometer at the ISIS spallation neutron source, UK. The performance of the new 10B4C-based detector is compared to that of a standard 3He tube, operating at the instrument as a part of the detectors assembly. The results show that the upgraded detector has a better resolution and an efficiency of the same order of magnitude of a 3He-based detector. © 2018 EPLA.