Proton beam irradiation induces invisible modifications under the surface of painted parchment

Ion beam analysis plays an important role in cultural heritage (CH) studies as it offers a combination of simultaneous and complementary analytical techniques (PIXE/PIGE/RBS) and spatially resolved mapping functions. Despite being considered non-destructive, the potential risk of beam-induced modifications during analysis is increasingly discussed. This work focuses on the impact of proton beams on parchment, present in our CH in form of unique historical manuscripts. Parchment is one of the organic, protein-based CH materials believed to be the most susceptible to radiation-induced changes. Various modification patterns, observed on parchment cross-sections by optical and electron microscopy are reported: discoloration (yellowing), formation of cavities and denaturation of collagen fibers. Considerable modifications were detected up to 100 µm deep into the sample for beam fluences of 4 µC/cm2 and higher. The presence of ultramarine paint on the parchment surface appears to increase the harmful effects of proton radiation. Based on our results, a maximum radiation dose of 0.5 µC/cm2 can be considered as ‘safe boundary’ for 2.3 MeV PIXE analysis of parchment under the applied conditions.

PM₁₀ variation, composition, and source analysis in Tuscany (Italy) following the COVID-19 lockdown restrictions

To control the spread of COVID-19, in March 2020 exceptional restrictive measures were taken imposing a radical change in the lifestyle of millions of citizens around the world, albeit for a short period of time. The national lockdown, which in Italy lasted from 10 March to 18 May 2020, was a unique opportunity to observe the variation in air quality in urban environments in a condition of almost total traffic block and a strong reduction in work activities. In this paper, the data from seventeen urban monitoring sites in Tuscany are presented by comparing PM and NO2 of the two months before the start of the lockdown and the two after with the corresponding months of the previous three years. The results show that the total load of PM2.5 and PM10 decreased but it did not exhibit significant changes compared to previous years, while NO2 undergoes a drastic reduction. For three of these sites, the chemical composition of the collected samples was measured by thermo-optical, ion chromatography and PIXE analysis, and the application of multivariate PMF analysis allowed the PM10 source identification and apportionment. Thanks to these analyses it was possible to explain the low sensitiveness of PM10 to the lockdown effects as due to different, sometimes opposite, behaviors of the different sources that contribute to PM. The results clearly indicated a decline in pollution levels related to urban traffic and an increase in the concentration of sulfate for all sites during the lockdown period.

ANALYSIS OF ILKHANIDS SILVER COINS DISCOVERED IN THE GREAT MOSQUE OF ARDABIL CITY IN NORTHWESTERN IRAN, BY PIXE METHOD

Город Ардебиль - один из древних городов Ирана, где сохранилось более 10 исторических памятников доисламского и исламского периодов, в частности, остатки Большой мечети - одной из первых больших мечетей Ирана, некогда возвышавшейся на берегу реки Балыклы-Чай. В 2009-2012 гг. в ходе работ по восстановлению Большой мечети было обнаружено множество монет: золотых византийских, медных - эпохи Атабеков и серебряных - династии Илханидов XI-XIII вв. Этот факт указывает на использование данного религиозного памятника в течение длительного времени. В статье подробно описывается методика исследования серебряных монет, найденных в Большой мечети и связанных с началом истории Илханидов. Результаты анализа элементного состава металла пяти монет методом PIXE - высокое содержание серебра и наличие золота вместе со значительным снижением содержания меди -свидетельствуют о благоприятных экономических условиях и расцвете культуры в период правления Илханидов. Авторы предполагают, что и серебро, и медь добывались в месторождениях, находившихся в окрестностях Тебриза. Existence of more than 10 historical sites dating back to pre-Islamic and Islamic periods, especially, the architectural remains of the Great Mosque located on bank of the Balikhlli chai river running through Ardabil indicates the significance of the city of Ardabil. Numerous Byzantine golden coins, Atabegs copper and Ilkhanids silver coins belonging to 11th to 13th centuries AD were found during the extensive activities on reparation of the Great Mosque in 2009-2012. This fact evidences that this religious monument has been used for a long time. The article focuses on Ilkhanids silvers coins. The investigation of the silver coins from the Great Mosque shows that they are related with the beginnings of Ilkhanids' history. PIXE analysis of some of the silver coins shows high purity of silver and gold in metal composition of coins and points to good economic conditions, medicine improvement and cultural dehiscence during Ilkhanid period and the preceding periods. The authors suppose the extract of copper and presence of silver in Tabriz surroundings.

Adsorption evaluation of large-size HDEHP/SiO2-P adsorbent investigated by micro-PIXE analysis

The Zr and Mo removal from HLLW is the current issue for repeated usage of the CMPO/SiO2-P-packed column. The adsorbability of the 2-mm-sized HDEHP/SiO2-P adsorbent, which was prepared by fabricating a SiO2 particle from the vibration cutting method and adapting a new polymerization method, was evaluated by the batch-wise adsorption experiment. In spite of the impregnation ratio of the HDEHP extractant, the extraction of Zr and Mo ions from the simulated HLLW was achieved but lanthanide ions e.g., Nd and Gd were also extracted as a minor component. Such unusual adsorption behavior of lanthanide ions could be only provided by accurate, sensitive and reliable micro-PIXE analysis.

Development of a 20MeV proton particle-induced X-ray emission analysis method in a helium atmosphere

We developed a 20[Formula: see text]MeV particle-induced X-ray emission (PIXE) analysis method using a medical cyclotron, which is conventionally used for positron emission tomography analysis performed in vacuo, during which the target sample is damaged. For non-destructive analysis and ease of switching between target samples, we developed a technique allowing 20[Formula: see text]MeV proton PIXE analysis to be performed at the atmospheric pressure. We filled the PIXE analysis chamber with helium and checked that the continuous background of the Compton tails of nuclear reaction [Formula: see text]-rays increased only minimally, and that the quasi-free electron bremsstrahlung (QFEB) did not increase at all, in the X-ray energy spectrum.

Analysis on adsorbent for spent solvent treatment by micro-PIXE and EXAFS

The spent PUREX solvent containing U and Pu is generated from the reprocessing process of spent nuclear fuel. The nuclear material removal is important for the safe storage or disposal of the spent solvent. Our previous study revealed that the adsorbent with the iminodiacetic acid (IDA) functional group is one of the most promising materials for designing the nuclear material recovery process. Accordingly, an IDA-type adsorbent was synthesized by using graft polymerization technology or a chemical reaction to improve the adsorption rate and capacity. The synthesized IDA-type adsorbent was characterized by micro particle-induced X-ray emission (PIXE) and extended X-ray absorption fine structure (EXAFS) analyses. The micro-PIXE analysis revealed that Zr was adsorbed on the whole synthesized adsorbents and quantified the microamount of adsorbed Zr. Moreover, EXAFS suggested that Zr in the aqueous solution and solvent can be trapped by the IDA group with different mechanisms.

Comparison of trace elements in freshwater pearls cultured in Japan, China, and USA

In this paper, we performed PIXE analysis of trace elements in freshwater pearls cultured in four different areas: Lake Biwa (Japan), Lake Kasumigaura (Japan), an unidentified lake in China, and Kentucky Lake (USA). We investigated the difference of trace elements contained in the four pearls from different aquaculture environments. The observed trace elements are Mn, Fe, Cu, Zn, and Sr. The major trace elements are Mn, Sr for all the samples. From comparison of the proportions of elements contained, we found the following features: (1) The Kasumigaura pearl has a nucleus with a high Mn/Sr ratio, (2) The Biwako pearl is low in iron content, and (3) The American pearl has high in Fe/Sr, Cu/Sr, and Zn/Sr ratios.

FT-IR measurement on the damage of Japanese paper induced by PIXE analysis

Analysis of cultural heritage samples by PIXE involves the risk of damaging precious samples due to MeV-proton irradiation. To investigate appropriate methods to detect invisible damage due to PIXE analysis, we analyzed the change in chemical bonding of the sample surface subjected to PIXE and RBS measurement by Fourier Transform InfraRed spectroscopy (FT-IR). We used Japanese hemp paper as a simulated cultural property sample. The proton irradiation for the PIXE/RBS measurement was performed in a vacuum with an incident beam energy of 2.5 MeV, a beam current of 1 nA, and an irradiation time up to 10 min. The corresponding beam flux and fluence were 0.06 nA/mm2 and 4 [Formula: see text]Coulomb/cm2, respectively. When the irradiation time was 10 min, the absorbed dose was 480 kGy on the sample surface. We identified neither change of elemental composition nor visible change such as discoloration due to irradiation. However, we found changes in peak heights in the measured FT-IR spectra, which suggest the destruction of chemical bonds such as O–H and C–O due to proton-induced radiation damage.

Quantification of major and trace elements contained in aircraft JET A-1 fuel by in-vacuum PIXE analysis

To characterize the chemical composition of aircraft exhaust particles, we developed a treatment method of jet fuel for an elemental analysis by an in-vacuum PIXE system. Eleven elements (Si, S, Cl, K, Ca, Cr, Fe, Ni, Cu, Zn, and Pb) were identified from each sample. The concentrations of S from five JET A-1 fuel samples collected on different days ranged from 30.4 to 440 wt.-ppm. The concentration level of S agreed well with the measurement results obtained by an in-air PIXE analysis, which we have previously performed to determine the major content elements and their concentration levels. Nine elements out of the identified 11 elements (Si, Cl, K, Ca, Cr, Ni, Cu, Zn, and Pb), which were not detected by the in-air PIXE analysis, were detected in all the JET A-1 fuel samples measured. Among these elements, Si, Ni, Cu, Zn, and Pb were found to be the major components. It is suggested that particles emitted from aircraft jet engines, which are generally in the size range smaller than 100 nm (ultrafine particles: UFPs), may contain Si, Ni, Cu, Zn, and Pb. These findings provide useful insights into the source apportionment of UFPs in and around airports.

Quantitative Analyses of Urinary Uranium by µ-PIXE

Simple methods for the determination of elements in biological fluids have been developed. It is important to quantify the accidental incorporation of radionuclides during the decommissioning work at nuclear power plants. Herein, we proposed the simple preparations and determination methods of uranium concentrations in urine for microbeam scanning particle induced X-ray emission (µ-PIXE) analysis in a rat model. A droplet (1 µL) of mixed solution of urine treated with a five-fold amount of concentrated nitric acid was placed on polypropylene film coated with perfluoroalkoxy alkanes (PFA) and dried at room temperature. The µ-PIXE imaging analysis revealed that successful condensation with homogeneous distribution of uranium in the specimen was achieved using by PFA coating. Uranium concentrations in the urine collected from uranium-injected rats were quantified. The obtained results were consistent with those determined by inductively coupled plasma mass spectrometry.