The aim of the present research is to validate the combined use, through data fusion, of a Laser Induced Fluorescence (LIF) scanning system and a radar scanner (RGB-ITR, Red Green Blue Imaging Topological Radar system), as a unique tool to address the need for non-invasive, rapid, and low-cost techniques for both diagnostic and operational needs. The integrated system has been applied to the House of Diana complex in Ostia Antica. The main diagnostic objective of this research was to trace the materials used in different phases of restoration, from antiquity to modernity, on both masonry and pictorial surfaces, to reconstruct the history of the building. Due to the significant interest in this insula, other studies have been recently carried out on the House of Diana, but they once again highlighted the necessity of multiple approaches and non-invasive methods capable of providing quasi-real-time answers, delivering point-by-point information on very large surfaces to overcome the limits related to representativeness of sampling. The data acquired by the RGB-ITR system are quantitative, allowing for morphological and 3-colour analysis of the investigated artwork. In this work, the sensor has been used to create coloured 3D models useful for structural assessments and for locating different classes of materials. In fact, the LIF maps, which integrate knowledge about the original constituent materials and previous conservation interventions, have been used as additional layers of the tridimensional models. Therefore, the method can direct possible new investigations and restoration actions, piecing together the history of the House of Diana to build for it a safer future.

The application of laser-based spectroscopic systems in the field of cultural heritage is now well established. In particular, LIF (Laser-Induced Fluorescence)-based instruments present some features that make them particularly valid in the field of cultural heritage, where the respect and the conservation of the target must be maximum. In fact, they have the ability to work in situ at several meters of distance from the target, they are non-destructive, don't require sampling and can be portable while providing first results in real time. The technique's effectiveness as a diagnostic tool for cultural heritage materials, like paintings, wood and stone, has been demonstrated widely. As part of the ADAMO project, three marble busts, preserved in the Chigi Palace of Ariccia, attributed to the Bernini school have been analysed by LIF to obtain information on constituent materials and on previous restoration processes, not available in this case. Two different LIF systems developed by ENEA have been used, to reduce the time for measurements and to limit the number of measurement points. Data post-processing has highlighted areas with treatments completely invisible to the naked eye as well as some differences on the surfaces of the various busts. Moreover, Raman measurements have been carried out in situ on the same busts by using a high-performance laboratory Raman system coupled with optical fiber head confirming the LIF results on the investigated samples.

Since the 2018 IAEA FEC Conference, FTU operations have been devoted to several experiments covering a large range of topics, from the investigation of the behaviour of a liquid tin limiter to the runaway electrons mitigation and control and to the stabilization of tearing modes by electron cyclotron heating and by pellet injection. Other experiments have involved the spectroscopy of heavy metal ions, the electron density peaking in helium doped plasmas, the electron cyclotron assisted start-up and the electron temperature measurements in high temperature plasmas. The effectiveness of the laser induced breakdown spectroscopy system has been demonstrated and the new capabilities of the runaway electron imaging spectrometry system for in-flight runaways studies have been explored. Finally, a high resolution saddle coil array for MHD analysis and UV and SXR diamond detectors have been successfully tested on different plasma scenarios.

Teeth are usually targeted for dating archaeological sites because they are less prone to dissolution, in comparison with bones. However, despite this apparent resistance, teeth do undergo diagenesis, which needs to be accounted for in order to obtain accurate ages. In particular, the uptake of trace elements such as uranium in dental tissues needs to be considered for dose rate determination when dated using electron spin resonance (ESR). Characterising the mineralogy and structural integrity of samples prior to dating may thus provide important information related to their state of preservation, especially in the case of teeth whose U content can significantly affect the dose rate. In this study, we dated five teeth of small-sized bovids using combined ESR/U-series dating. They were collected at the Middle Stone Age site of Lovedale, located in the central interior of South Africa. Micromorphology provided sedimentary context to the samples, which were recovered from a layer of gravel rich in faunal remains. Using cathodoluminescence, laser-induced fluorescence, Fourier transform infrared spectroscopy and Raman micro-spectroscopy we assessed the degree of preservation of the enamel. Results reveal that carbonate hydroxyapatite underwent post-depositional alteration, based on its molecular structure and elemental composition. Although the teeth all originate from the same layer and were sampled in the same 1-m square and at a similar elevation, U-content in the enamel differs highly from one tooth to the other, with values ranging from 1.7 to 29.6 ppm. These values are correlated with equivalent doses (D-e) from 228 to 923 Gy and are consistent with variations in crystallinity determined with vibrational spectroscopy. We also investigated the possible saturation of the ESR signal, by repeating measurements with microwave power values from 1 to 20 mW. Despite such diversity in U-content, the ages calculated assuming an early uptake of U all fall within the same range, from 63 +/- 8 ka to 68 +/- 15 ka and may only represent a minimum estimate.

Laser Induced Fluorescence (LIF) is a well-recognized spectroscopic technique in cultural heritage for non-destructive surface chemical analysis. It is particularly suitable for in situ analysis on delicate targets as artworks, because it does not need any sample preparation nor contact, working remotely also where only optical access is available. Recently ENEA has developed two LIF prototypes with multispectral (Forlab) and hyperspectral (Lifart) scanning systems, that return different typologies of results, making them necessary and dependent each other. In fact, Forlab permits by its motorized optics the rapid acquisition of fluorescence maps and images of large surfaces in specific spectral wavelengths, while Lifart returns complete fluorescence spectra, giving a complete spectral information of an object. In this paper the intercalibration of two systems is reported, with the data analysis of calibration samples and a software to automatically correct imaging data, that take into account Forlab filters bandpasses and optical efficiencies, in order to make these two configurations as much as possible comparable. The new correcting algorithm was also tested on LIF measurements carried out on an Egyptian casket and sarcophagus, obtaining higher quality fluorescence images.

In this work we report on the Laser-Induced Breakdown Spectroscopy (LIBS) characterization of the Frascati Tokamak Upgrade (FTU) first wall (FW) and toroidal limiter after the spring-summer 2019 experimental campaign. We performed our analysis by using a compact LIBS system mounted on the FTU robotic arm, entering the FTU vacuum vessel (VV) and measuring the FW elements in-situ. The LIBS system was expressly designed and developed for this task and, to our knowledge, it represents the first prototype of LIBS mounted on a robotic arm for analyses inside a tokamak. It allows to perform measurements at (1) atmospheric pressure or (2) in vacuum (down to 10- 2-10- 3 mbar) or (3) under gas flux (He, Ne, Ar etc.) and is suitable for 4) single pulse or 5) double pulse LIBS measurements. The LIBS analyses revealed the main chemical components of the stainless-steel FTU FW, Mo and Ti from the Titanium-Zirconium-Molybdenum alloy (TZM) tiles of the toroidal limiter. A superficial contamination of Li, originating from past liquid lithium limiter experiments was also clearly revealed. To simulate a LIBS analysis of a component of the ITER divertor region we placed a metallic sample at the bottom of the FTU VV through a sample holder and we measured it with the LIBS system. The stratigraphy of this ITER-like sample, composed of an Al/D superficial layer 3 mu m thick (D 5% atomic concentration, Al as proxy for Be) on a W substrate simulates ITER PFCs in the divertor baffle and was characterized with high axial resolution (few hundreds nm for each laser shot) although the D signal from the D alpha emission line at 656.1 nm was found strongly interfering with the corresponding H alpha emission at 656.28 nm from the environmental hydrogen.

In order to try to improve spectral separation for hydrogen isotope detection in plasma facing components, a flow of noble gas at reduced pressure is proposed as alternative to atmospheric pressure experiments in air during maintenance of fusion vessels. To this aim the already realized compact LIBS probe has been equipped with a sealable tip where a noble gas could flow. The tip was in contact with the selected point of the target and its proper positioning was guaranteed by an adjustable metallic cone. Laboratory measurements were carried out by flowing either He or Ar on ITER-like tiles. A positive effect of Ar flow on H alpha signal intensity was observed, while a significant narrowing of the H alpha band was obtained upon He addition. Additional measurements on deuterium doped samples simulating the tile's composition in ITER divertor region were performed by applying a local vacuum in the point of analysis or utilizing the set-up in double pulse (DP) mode. These experiments were aimed at optimizing the acquisition parameters of the LIBS setup (e.g, single or double pulse excitation, gate delay, gate width, interpulse delay) when operated in different conditions (vacuum, atmospheric pressure, under gas flow) in order to resolve the two nearby emission bands H alpha and D alpha, still preserving a satisfactory Signal-to-Noise-Ratio (SNR). Finally, considerations on applicability of Calibration Free (CF) method for the quantification of hydrogen isotopes are presented.

Cultural heritage protection and safeguarding is a clear problem for the worldwide community because the legacy and identity of communities has to be kept alive and transmitted to future generations. To this end optical technologies have an important role to play in defining state-of-the-art conservation, guiding restauration, and exploring new opportunities in virtual and augmented realities where other complementary information can be merged. ENEA has developed different laser-based sensors for remote and local diagnostics that have already been deployed in field campaigns implementing different spectroscopic techniques that supply prompt information in real time and are non-destructive and non-invasive as regards the artifact being studied. Here the technical characteristics and performances of the tools are briefly described, and examples provided of monitoring applications of paintings, statues, woods, metals and structural observations (tensions and vibrations).

Artistic surfaces at the Bishop’s Palace of Frascati have been investigated by an integrated approach involving different non-invasive diagnostic techniques. A LIF (Laser Induced Fluorescence) scanning system worked in synergy with the RGB-ITR ((Red Green and Blue – Imaging Topological Radar) 3D laser scanner and the SfM (Structure from Motion) technique for the 3D photogrammetric reconstruction. The presented case study shows how 3D multispectral information can reveal and locate previous restoration actions and deterioration processes as support for conservation, research and dissemination purposes.

Optical and spectroscopic techniques offer unique possibilities for non-destructive or micro-destructive characterization of painted Cultural Heritage surfaces. The development of fast laser scanners in combination with sensitive CCD detector gave the chance to design and operate portable systems suitable to in-situ an remote spectroscopic imaging. Different prototypes have been developed and patented to collected reflectance and fluorescence images excited at different ultraviolet and visible laser wavelengths, Raman and LIBS signals. Portable integrated instruments suitable for operation at different distance from a 1.5 to 30 m, have been assembled and operated in laboratory on multilayered samples and in field campaigns on CH painted surfaces carried out within the COBRA and ADAMO regional projects. Results obtained on painted surfaces on monuments in Latium will be presented demonstrating the potentiality of combined in situ use of optical and spectroscopic tools in solving specific CH characterization problems.

The amount of tritium (T) retained in plasma facing components (PFCs) and in-vessel structures has to be carefully monitored in ITER because of the limits fixed by safety issues. Laser-Induced-Breakdown-Spectroscopy (LIBS) is one of the eligible techniques for this task because it does not require any sample pre-treatment (or removal), it can work both in atmospheric pressure or in vacuum, with different background gases. LIBS can be set up both on a robotic arm entering the vacuum vessel or outside it, for analyses during shut-down periods or in-between plasma discharges. In this paper we describe a new, compact LIBS system, mounted on the Frascati Tokamak Upgrade (FTU) robotic arm, to perform measurements on ITER-relevant samples placed in the FTU mock-up. The samples, composed of thin layers (few mu m) of W, Al, D, simulate the co-deposition of Be with T on ITER divertor tiles (Be and T are replaced by Al and D in the samples). W, Al, D emission lines has been clearly detected, both as major constituents or in trace quantities, with different background gases using a single laser pulse.

Nowadays scientific study of Cultural Heritage accompanies most of the time historical artistic evaluation and an assessment of the conservation state by humanistic experts and restorers. Several laboratory methods with high sensitivity are well established (ICP-MS, FTIR,…), and many methods for in situ rough characterization of large surface are widely diffused (thermovision, UV photography,…), in addition to instrumentation for punctual analysis to be applied also in field (XRF, colorimetry,…). However, the request for systems that can provide rapid detailed characterization on large surface in any storage conditions is still a hot topic. This is combined with the ever-increasing demand for digital material for documentation, fruition and study. Laser-based systems, and in particular Laser Induced Fluorescence (LIF), Laser Induced Breakdown Spectroscopy and Raman spectroscopy, due to the characteristics of these sources and the detectors to which they can be coupled, respond well to these needs. The TECFIS-DIM (Diagnostic and Metrology) Laboratory of the ENEA center of Frascati (Rome, Italy) in the last decade has put an effort to develop more and more compact and efficient laser systems for in situ material characterization on cultural heritage surfaces. Here two prototypal LIF systems have been used to characterize marble surfaces treated with ancient and modern materials and a rapid recognition and mapping method has been developed and tested thanks to the individuation of discriminant spectral features. Results are reported on test samples created in lab with known substances and in situ on real artworks.

ABSTRACT Accurate radiocarbon ( 14 C) dating of lime mortars requires a thorough mineralogical characterization of binders in order to verify the presence of carbon-bearing contaminants. In the last 20 years, cathodoluminescence (CL) has been widely used for the identification of geologic calcium carbonate (CaCO 3 ) aggregates and unreacted lime lumps within the particle size fraction selected for carbon recovery. These components are major sources of older and younger carbon, respectively, and should be removed to obtain accurate age determinations. More recently, laser-induced fluorescence (LIF) has provided another means of investigating the preservation state and composition of CaCO 3 binders. Considered the growing interest of the mortar dating community in the latest advancements of these analytical methods, here we review the principles of CL and LIF of CaCO 3 , their instrument setup, and their application to the characterization of ancient lime mortars used for 14 C dating. In addition, we provide examples of SEM-CL and LIF analyses using high-resolution instrumentation, we discuss current issues and propose future lines of research.

Optical and spectroscopic techniques offer unique possibilities for non destructive or micro-destructive characterization of surfaces, with widespread applications, starting from in-line monitoring of industrial processes. A significant group of industrial applications concerns nuclear grade material characterization and plasma diagnostics relevant to the thermonuclear fusion process. However, technologies and methodologies originally developed for specific in-vessel utilization, can easily find additional in-situ and remote application to environmental and cultural heritage (CH) diagnostics addressed to preventive conservation and restoration of surfaces. At ENEA Frascati different prototypes have been developed and patented to collect reflectance and fluorescence images excited at different ultraviolet and visible laser wavelengths, Raman and LIBS signals. Portable integrated instruments suitable for operation at different distances from a 1.5 to 30 m, have been assembled and operated in laboratory on multilayered samples and in field campaigns for Security and on CH painted surfaces. Significant results relevant to the cross fertilization among different applications will be presented and discussed.

In the frame of the COBRA (Conservation of Cultural Heritage through Radiation and Enabling Technologies) Regional project, several historical sites have been object of study by means of non-destructive techniques to analyze different kinds of artworks from different points of view, as structural modification or chemical degradation. The availability of information on the state of health of artworks quickly and as complete as possible can represent a great advantage for the optimization of the conservation and restoration actions. To this aim, several prototypes based on non-destructive laser based techniques have been developed at ENEA and encouraging results have been obtained by their application to some cases study supported by COBRA project. In this work, some results of the study of the Greek Chapel in the Priscilla's Catacombs in Rome performed by LIF (Laser Induced Fluorescence) Scanning, giving information regarding the surface chemical composition, will be reported. Particular attention has been devoted to the area indicated by the site referents as of special interest for the presence of an evident biological attack. In addition to the characterization of extended biofilms, LIF was also able to detect microorganisms from areas where biodegradation is not evident, suggesting the possibility of its early detection. This result can be of great usefulness for the site conservation. The analyses by standard laboratory techniques (e.g. microscope observations) prompt us to exclude the presence of photosynthetic microorganisms. For an easy and understandable vision of the obtained results, collected by different instruments, a post-processing and data fusion phase was needed.

In this paper the Laser Induced Breakdown Spectroscopy (LIBS) measurement of the deuterium (used as a proxy for tritium) retained in and the surface elemental composition of the FTU Mo (TZM) toroidal limiter tiles, carried out from remote (similar to 2.5 m) during short breaks of the operations or during machine maintenance, are reported. Single pulse technique has been used with the FTU vessel under high vacuum or in Nitrogen or Argon atmosphere. In vacuum experiments D-alpha and H-alpha lines have been detected with good resolution, while in Ar atmosphere (5 x 10(4) Pa) the two lines were partially overlapped due to Stark broadening. First results of measurements in N-2 atmosphere (10(5) Pa)showed no presence of D-alpha and H-alpha lines. These measurements were also carried out for supporting the foreseen use of a robotic arm for an extended LIBS analysis of retained deuterium in the FTU vessel components.

In nature, calcium carbonate (CaCO3) in the form of calcite and aragonite nucleates through different pathways including geogenic and biogenic processes. It may also occur as pyrogenic lime plaster and laboratory-precipitated crystals. All of these formation processes are conducive to different degrees of local structural order in CaCO3 crystals, with the pyrogenic and precipitated forms being the least ordered. These variations affect the manner in which crystals interact with electromagnetic radiation, and thus formation processes may be tracked using methods such as X-ray diffraction and infrared spectroscopy. Here we show that defects in the crystal structure of CaCO3 may be detected by looking at the luminescence of crystals. Using cathodoluminescence by scanning electron microscopy (SEM-CL) and laser-induced fluorescence (LIF), it is possible to discern different polymorphs and their mechanism of formation. We were thus able to determine that pyrogenic calcite and aragonite exhibit blue luminescence due to the incorporation of distortions in the crystal lattice caused by heat and rapid precipitation, in agreement with infrared spectroscopy assessments of local structural order. These results provide the first detailed reference database of SEM-CL and LIF spectra of CaCO3 standards, and find application in the characterization of optical, archaeological and construction materials.

Tritium (T) inventory in Plasma Facing Components (PFCs) will be one of the critical issues for ITER because of the impact tritium can have on the machine operation and safety. Laser Induced Breakdown Spectroscopy (LIBS) is a promising technique to accomplish this task, providing both qualitative and quantitative composition of the chemical elements retained in PFCs. LIBS does not require sample pretreatment or manipulation, it can work in-situ between fusion discharges or during maintenance periods, it is suitable for measurements at different residual pressures, with different background gases. It can detect all the chemical elements through their spectral emission. This paper presents the results of LIBS measurements at 100 mbar nitrogen pressure on metallic coating (W-Al-D) simulating the superficial composition of ITER divertor PFCs contaminated with nuclear fuel and material eroded from the first wall. LIBS spectra showed clear W, Al, D emission lines. A quantitative estimation of their relative concentration was performed by applying the Calibration Free (CF) analysis. CF does not require reference samples, so ifs particularly suitable for this purpose. CF results were compared with the nominal concentrations and were found in good agreement with the latter.

Since the 2016 IAEA Fusion Energy Conference, FTU operations have been mainly devoted to experiments on runaway electrons and investigations into a tin liquid limiter; other experiments have involved studies of elongated plasmas and dust. The tearing mode onset in the high density regime has been studied by means of the linear resistive code MARS, and the highly collisional regimes have been investigated. New diagnostics, such as a runaway electron imaging spectroscopy system for in-flight runaway studies and a triple Cherenkov probe for the measurement of escaping electrons, have been successfully installed and tested, and new capabilities of the collective Thomson scattering and the laser induced breakdown spectroscopy diagnostics have been explored.