X-ray analytical techniques are widely used in the world. By the way, due to the strong radiation–matter interaction, to design optical devices suitable for X-ray radiation remains still of wide ...interest. As a consequence of novel advanced material studies, in the last 30years several typologies of X-ray lenses have been developed. In this work, a short review on the status of Polycapillary Optics (polyCO), from design and fabrication to various applications, has been presented making comparison of the results achieved by several groups through different X-ray optical elements.
A focus is regarded for advanced X-ray imaging and spectroscopy tools based on combination of the modern polyCO hardware and the reconstruction software, available as homemade and commercially ones. Recent results (in three main fields, high resolution X-ray imaging, micro-XRF spectroscopy and micro-tomography) obtained at XLab Frascati have been discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Ice cores from inner East Antarctica provided some of the longest and most detailed climatic reconstructions and allowed understanding the relationships between atmospheric mineral dust and climate. ...In this work we present synchrotron radiation X‐ray Fluorescence geochemical data of dust from the TALDICE ice core drilled at Talos Dome, a peripheral ice dome of East Antarctica (Western Ross Sea). Results highlight a dominant southern South American origin for dust at TALDICE during the Last Glacial Maximum, similarly to other sites located further inland onto the polar plateau. On the contrary, a different scenario concerns Talos Dome during the Holocene if it is compared to more inner sites. The tight connection between high southern latitudes and Antarctica that characterizes cold climate stages becomes weaker since the onset of the last climatic transition and throughout the Holocene. The net effect of this process at Talos Dome is a modification of the atmospheric and environmental settings, owing to local Antarctic sources of Victoria Land to gain importance and become the dominant ones. At the same time in inner East Antarctica the provenance of dust remains remote also during Holocene, revealing an evolution of the homogeneous scenario observed in glacial periods. The enhanced sensitivity of peripheral ice sheet sites to local dust sources makes Talos Dome an ideal site to assess the climatic and atmospheric changes of the peripheral sectors of East Antarctica during the current interglacial period.
Plain Language Summary
During the Last Glacial Maximum, about 20,000 years ago, mineral dust from South America was massively transported toward Antarctica as a consequence of impressive environmental and climatic changes. Many ice cores drilled from the inner sectors of the Antarctic ice sheets support this scenario. Little is known when attention is shifted to peripheral areas and to interglacial periods. A new record of mineral particles at Talos Dome, a peripheral area of the East Antarctic ice sheet (Western Ross Sea sector), is here presented to partially close these gaps. Combining the data about concentration, composition, and grain size of the dust deposited at Talos Dome, it was possible to appreciate the influence played by local Antarctic dust sources to the depositional budget of the site. These local sources, corresponding to localized ice‐free areas, are extremely important when attention is given to the peripheries of the ice sheets. This is particularly true for interglacial periods, when the transport and the deposition of mineral dust from South America to Antarctica is much reduced.
Key Points
The dust cycle reacted differently to the last climatic transition in different regions of the East Antarctic Ice Sheet
The reduced transport of remote dust enhanced the emergence of a signal related to local dust dynamics in the Talos Dome ice core
The chemical index of alteration provides constraints to track ice core dust provenance, also in relation to its formation environment
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The quantitative evaluation of chemical elements from X-ray Fluorescence (XRF) analysis still remains a strong hurdle in X-ray Spectrometry, mainly due to significant matrix effects involved in the ...processes. The Fundamental Parameter Method (FPM) is a valid tool for the calculation of analyte concentration unless the primary source comes from a Synchrotron Radiation facility or the experimental design is based on a confocal layout. The approximation of an infinitely thin sample represents a feasible way to apply the FPM approach along with dedicated X-ray optics implemented in the XRF apparatus to improve the performance of the primary beam (and also of the fluorescence signal reaching the detector). This is routinely available at the XLab Frascati of INFN-LNF thanks to the ”Rainbow X-ray” (RXR) facility, the μXRF station opened to users and optimized for most of X-ray analytical research fields. The basic principle of the station is in the use of various geometrical combinations of polycapillary optics for X-ray beam shaping (focusing/collimation) applied to specially designed laboratory units. The flexible RXR layout allows investigating specimens of the dimensions ranging from several millimeters up to half meter and weighting up to several tens of kilograms with the main advantage of having a detection system able to work separately both at high and low X-ray energies. The aim of the present work is to show the results obtained in quantitative XRF analysis by applying the FPM approach to the RXR experimental layout in a study of the pigments covering two different Japanese scrolls, n.142 838 (also known as Engi Jizo Emakimono) and n. 142 846, coming from the private Ragusa Collection presently stored at Pigorini Museum in Italy.
•Layout with x-ray tube and polyCO demonstrated for Cultural Heritage.•Application of FPM to μXRF studies is a valid tool for quantitative XRF.•Use of approximation of “thin” samples resulted successful in pigments study.•XRF results confirmed pigments formulation given by historical data.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
4.
Shaped X-ray beams by channeling in polycapillary optics Hampai, D.; Guglielmotti, V.; Marcelli, A. ...
Radiation physics and chemistry (Oxford, England : 1993),
September 2020, 2020-09-00, 20200901, Volume:
174
Journal Article
Peer reviewed
Polycapillary optics (polyCO) is an x-ray optical unit used in different instruments in a wide variety of scientific and industrial applications. The optics works utilising the phenomenon of x-ray ...total external reflection at radiation transmission through the optics micro-channels. The polyCO devices, according to their geometries, are capable to focus x-ray beam, manipulate divergent or quasi parallel beams. Their use may reduce both size and weight of the device resulting in low power compact x-ray instruments. However, matching polyCO parameters is crucial for developing portable, remote or in-line, industrial sensors and novel instruments for materials science, chemical-environmental and bio-medical applications.
In this work we present the analyses of x-ray beam formed behind polyCO devices paying attention to the parameters such as the radiation flux, focal spot-size and divergence. X-ray techniques will be also discussed to outline state of the art of world-wide polyCO-based research.
•PolyCO optics manipulate X-ray beam to micro focal spot or quasi parallel beam.•PolyCO shape profile influences focal spot characteristics.•Identifying PolyCO profile parameters helps its fitting with X-ray techniques.•The characterization procedures are validated through simulated tracing software.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
5.
X-ray applications and recent advances @ XLab Frascati Dabagov, S. B.; Hampai, D.; Guglielmotti, V. ...
Atti della Accademia nazionale dei Lincei. Rendiconti Lincei. Scienze fisiche e naturali,
06/2020, Volume:
31, Issue:
2
Journal Article
Peer reviewed
Open access
XLab Frascati is a facility open to external users for different X-ray analyses, ranging from structural studies through X-ray diffraction to elemental mapping by means of µX-ray Fluorescence, colour ...tomography and X-ray imaging studies. This is possible thanks to our experimental layouts XENA (X-ray Experimental station for Non-destructive Analysis) and RXR (Rainbow X-Ray) along with our facility for the production of polycapillary optics. The know-how on these optics enable us improving the performances of our setups by adopting the best fitting X-ray optics according to the experimental requirements. To make an example, the main advantage of RXR is that the detection system includes two spectrometers working in high (arranged in the polycapillary confocal geometry) and low X-ray energies,, respectively, permitting both the 2D µXRF scan and 3D µXRF elemental mapping (colour tomography) due to the confocal geometry with a 3-axis fine motion system. The article showcases the results obtained in key case studies where we performed: (i) 2D/3D µXRF to analyse chemical composition of tree rings with respect the influence of the environmental context, to study a “fresco” fragment and assess the presence of damages, to make a 3D reconstruction of a screw encapsulated in glue through the its elemental composition as well as (ii) X-ray imaging and (iii) µCT/dynamic CT to characterize LiF detectors, to study the structure of a flower bud and to evaluate the profile distribution of a diesel spray from the nozzle.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Quantitative elemental determination for concentrations in the ppb range requires a careful preparation of the sample. In particular, for elemental analysis of very low concentration samples, less ...than 1ng/mm2, a very bright X-ray source, typically synchrotron radiation (SR) in total external reflection fluorescence regime (SR-TXRF), is required. Here, we wish to demonstrate that a conventional source combined with a polycapillary semi-lens can provide a quasi-parallel beam intense enough for desktop TXRF analysis of low concentration samples.
•Total Reflection X-ray Fluorescence for very low concentration analisys.•Qualitative and quantitative information from trace elements in the ppb range.•Conventional source with polycapillary optics instead Synchrotron Radiation.•Possibility to perform the technique in all kind of laboratories.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The Muon g−2 experiment, E989, is currently taking data at Fermilab with the aim of reducing the experimental error on the muon anomaly by a factor of four and possibly clarifying the current ...discrepancy with the theoretical prediction. A central component of this four-fold improvement in precision is the laser calibration system of the calorimeters, which has to monitor the gain variations of the photo-sensors with a 0.04% precision on the short-term (∼1ms). This is about one order of magnitude better than what has ever been achieved for the calibration of a particle physics calorimeter. The system is designed to monitor also long-term gain variations, mostly due to temperature effects, with a precision below the per mille level. This article reviews the design, the implementation and the performance of the Muon g−2 laser calibration system, showing how the experimental requirements have been met.
The Muon g-2 Experiment at Fermilab (E989) will measure the muon magnetic anomaly with unprecedented precision (0.14 ppm), which yields a factor of 4 improvement with respect to the previous ...measurements at Brookhaven National Laboratory (BNL) (E821). To achieve this goal, the relative response of each calorimeter channel must be calibrated and monitored at a level better than <inline-formula> <tex-math notation="LaTeX">10^{-3} </tex-math></inline-formula> in the time window of the muon fill. The calibration system uses a laser source and photodetectors. The data acquisition (DAQ) of the system is designed around two field-programmable gate array (FPGA)-based boards and a custom crate bus. The front-end board manages the photodetector operation and signal processing and performs a first-level data concentration task. Up to 12 FPGA boards can be housed in a 6U crate. A readout master controls the boards, implements event-building functionalities, manages the monitoring interface, and facilitates calibration and debugging tasks. A gigabit-ethernet interface is used to transfer data to the on-line farm for storage and further processing. Presently, the system is working at Fermi National Accelerator Laboratory (FNAL). In this article, we present the DAQ system design, run control user interface, and system evaluation.
The present work reports on Yttrium based photocathodes. A Yttrium (Y) thin film is deposited via pulsed laser deposition (PLD) on the copper (Cu) back flange of a radio frequency (rf) gun for ...photocathode application. Because of a lower work function with respect to Cu, Y photocathodes are particularly appealing for the possibility to illuminate them with visible laser pulses, with the advantage of a higher energy per pulse, paving the way to high repetition rate photoinjectors, driven by conventional laser sources. In addition, working atλ∼400nmthe small energy difference between the Y work function (about 3 eV) and the laser photon energy reduces the contribution of the intrinsic emittance of the material. Photoelectrons, emitted by the thin film Y photocathode driven by the second harmonic of a Ti:Sapphire laser, have been characterized in terms of quantum efficiency and transverse emittance. Results have been compared with the theoretical ones obtained by the three-step model of Spicer for metallic photocathodes.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM, UPUK
Mu2e will search for the Charge Lepton Flavor Violating (CLFV) conversion of a muon into an electron in the field of a nucleus. A clean discovery signature is provided by the mono-energetic ...conversion electron (
E
e
= 104.96 MeV). If no events are observed, Mu2e will set a limit on the ratio between the conversion and the nuclear capture rate below 3 × 10
−17
(at 90% C.L.). In order to confirm that the observed candidate is an electron, the calorimeter resolution requirements are to provide
E
res
< 10%,
T
res
< 500 ps for 100 MeV electrons while working in vacuum and in a high radiation environment and high magnetic field. The calorimeter is made of two annular aluminum disks, each one filled with 674 pure CsI crystals read out by SiPMs. A sophisticated mechanics and cooling system has been developed to support the crystals and cool the sensors. Radiation hard analog and fast digital electronics have been developed. In this paper the QC tests performed on the produced components and the construction status are reported, as well as the results obtained on the large size prototype with test beam data and at a cosmic ray test stand.
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