The atmospheric tests of nuclear weapons caused a sudden increase in the radiocarbon concentration in the atmosphere from 1955, reaching its maximum value in 1963–1965. Once the nuclear tests in the ...atmosphere were halted, the
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C concentration started to decrease. This behavior of the radiocarbon concentration is called the “Bomb Peak”, and it has successfully been used as a tool for high-precision radiocarbon measurements, in forensic sciences and biology. In the art field, the possibility of dating canvas, wood and paper, widely used as supports for paintings, may be an invaluable tool in modern art studies.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract After exploring different solutions and testing several options, the high granularity resistive Micromegas technology is now mature enough to offer an efficient operation up to particle ...rates of 10 MHz/cm 2 , maintaining the gas amplification above 10 4 , with a large margin before breakdown in order to ensure a stable and reliable operation. The detector exploits small-size readout pads for occupancy reduction and a double Diamond-Like Carbon (DLC) resistive layer with a network of dot-connections to ground for a fast charge evacuation. The double-layer allows preserving the minimum resistance to suppress the discharge intensity for stable operations. The performance measured with particle beams at CERN have shown a spatial resolution below 100 μm for mm-wide readout pads and a few ns time resolution. Now, the technology is being scaled to larger areas, with the construction of detectors with an active area of ∼20×20 cm 2 (already achieved) and new ∼40×50 cm 2 prototypes under construction. An overview of the detector technology, including the latest results, is presented in terms of the gain and rate capability (measured in the laboratory) and efficiency, time and spatial resolution (measured at the CERN SPS). Possible applications in HEP experiments, as well as future developments, are also reported.
•The neuropsychological tests are not only associated with metallic pollutants (Hg) measured with biomonitoring.•Socio Economical Status and parents educational level have an impact on the child's ...neuro development, diet and behavior.•Live in areas closer an industrial plant plays a role in the cognitive impairment and in lower IQ.•Lower IQ scores are associated with an increase of attention/hyperactivity problems and social behavior.
Although high or repeated exposure to different forms of Hg can have serious health consequences, the most important toxicity risk for humans is as methylmercury (MeHg) which exposure is mainly through consumption of fish. Generally, more than the 80% of Hg in hair is as MeHg, which is taken up by hair follicles as MeHg-cysteine complexes. In this context, hair samples were collected from 200 children (7 years) living in a coastal site in the North-East (A) of Italy and from 299 children (6–11 years) living in a urban area of South of Italy (B) to determine the levels of MeHg. Considering the neurotoxicity of MeHg, children were subjected to cognitive and neuropsychological tests. The hair values of Hg in the children population groups were comparable with data reported in other international surveys. On the other hand, combining results of the neurological tests with Hg levels, a possible relationship between Hg and an increase of the errors average reported in some neurological tests has been noted. Although the Hg levels were not elevated, a possible neurological influence in children, a population more susceptible than adults, might not be excluded, but the influence on neurological performances of the children could be also due to the family environment (socio economic status, educational level, etc.).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The R&D project being presented aims to improve the use of resistive Micromegastechnology in high-energy physics experiments. The project focuses on achieving stable, reliable,and high-gain operation ...at particle flow rates above 1 MHz/cm2 on largesurfaces. To achieve this, the project uses a configuration with small pads readout and requiresinnovative solutions for the spark protection resistive scheme. Different resistive patterns wereinvestigated, and finally the solution based on a double layer of DLC foils was chosen,demonstrating the capability to perform equally for low and high rates under irradiation of X-rayson the full surface of 25 cm2 of the prototype detectors. With this technologyand layout, a detector with an active area of 400 cm2 was recently built. Inthis work we present the results of high-rate capability, robustness, dependence on the irradiatedarea, obtained with high intensity X-rays measurements, as well as the results on efficiency andspatial resolution obtained, at low rates, at CERN SPS with high energy particlebeams. Additionally, preliminary results of pixelized resistive Micromegas time response arereported. With the successful achievements of this detector and the construction of even largersmall-pad resistive Micromegas next year, the project will establish the technology for future usein particle physics and other applications.
Background
Nickel (Ni) dermatitis remains a highly prevalent allergic condition in Italy. There is a continuous need for clinical and epidemiological surveillance to evaluate whether or not European ...Ni Directive has been effective in contact allergy prevention.
Objectives
To assess the prevalence of Ni dermatitis among patch‐tested patients and self‐interviewed school students and to analyse Ni release from earlobe jewellery.
Methods
Results of patch tests performed in 2006–2007, 2015–2016 and 2017–2018 were retrieved. A questionnaire was compiled by 315 secondary school students. Ni release from earring parts was analysed with the EN1811:2015 method.
Results
A significant time trend of decreasing Ni positivity from 2006–2007 to 2017–2018 was observed both in the overall population (44.1% in 2006–2007, 33.0% in 2015–2016, 31.6% in 2017–2018, P < 0.0001) and in female patients (P < 0.0001). Conversely, change was not significant in males (P = 0.16). Decrease was significant for all age groups, except for those aged >60 years (P = 0.51). Among 242 students who reported earring use, 130 (54%) reported symptoms at earlobes, mostly associated with jewellery of materials other than gold and silver (59% of those with earlobe symptoms). Ni release exceeded the migration limit in 4/21 (20%) earring parts.
Conclusions
A high prevalence of Ni dermatitis and earlobe symptoms were found in Rome. A decreasing time trend was noted, with a significant decline in Ni sensitivity compared to the situation observed right after Ni Directive implementation. This most likely represents the consequence of reduced Ni content in earring parts, although a major care in the use of Ni‐containing objects could contribute to explain these findings.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
We present the development of resistive Micromegas with small pad readout aiming at precision tracking without efficiency loss up to several MHz/cm2. Several prototypes have been built with the spark ...protection resistive layer deposited with different techniques: a pad-patterned embedded resistor layout with screen printing, and a uniform layer by sputtering (Diamond Like Carbon structure). All detectors consist of a matrix of 48 × 16 rectangular shaped pads with a pitch of (1 × 3) mm2. The active surface is (48 × 48) mm2 with a total number of 768 channels, routed off-detector for readout. Characterization and performance studies of all prototypes have been carried out by means of radioactive sources, X-rays, cosmic rays and high energy particle beams. A comparison of prototypes with different resistivity layout will be presented.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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Small-pads resistive Micromegas prototype Di Donato, C.; Alviggi, M.; Camerlingo, M.T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Volume:
958
Journal Article
Peer reviewed
Detectors at future accelerators will require operation at rates up to three orders of magnitude higher than 15 kHz/cm2 the hit rates expected in the current upgrades forward muon detectors of LHC ...experiments. A resistive Micromegas detectors with modified readout system can achieve rate capability up to few MHz/cm2 low occupancy. We present the development of small-pad Micromegas detectors with a pad resistive readout of few mm2 in size, built with the spark protection resistive layer realized with different techniques.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The new generation of particle physics experiments at current and future colliders demands more and more robust detectors. A proposed solution to the stringent requirements are the Small-pad ...Resistive Micormegas. This technology is being developed during recent years, in the framework of the new R&D project RHUM. Different resistive schemes have been implemented. The different behaviours of the embedded resistor layout and the Diamond-Like Carbon (DLC) uniform layers scheme have been studied. Results at very high rate are shown. HV stability studies with two different gases are reported.
The performance and long term stability of an optically readout Time Projection Chamber with an electron amplification structure based on three Gas Electron Multipliers was studied. He/CF4 based gas ...mixtures were used in two different proportions (60/40 and 70/30) in a CYGNO prototype with 7 litres sensitive volume. With electrical configurations providing very similar electron gains, an almost full detection efficiency in the whole detector volume was found with both mixtures, while a light yield about 20% larger for the 60/40 was found. The electrostatic stability was tested by monitoring voltages and currents during 25 days. The detector worked in very stable and safe condition for the whole period. In the presence of less CF4, a larger probability of unstable events was clearly detected.
The CYGNO project has the goal to use a gaseous TPC with optical readout to detect dark matter and solar neutrinos with low energy threshold and directionality. The CYGNO demonstrator will consist of ...1 m3 volume filled with He:CF4 gas mixture at atmospheric pressure. Optical readout with high granularity CMOS sensors, combined with fast light detectors, will provide a detailed reconstruction of the event topology. This will allow to discriminate the nuclear recoil signal from the background, mainly represented by low energy electron recoils induced by radioactivity. Thanks to the high reconstruction efficiency, CYGNO will be sensitive to low mass dark matter, and will have the potential to overcome the neutrino floor, that ultimately limits non-directional dark matter searches.
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