The high luminosity upgrade of the Large Hadron Collider, foreseen for 2027, requires the replacement of the ATLAS Inner Detector with a new all-silicon Inner Tracker (ITk). The expected total ...integrated luminosity of 4000 fb−1 means that the strip part of the ITk detector will be exposed to a large radiation fluence of up to Φeq = 1.6 × 1015 1 MeV neq/cm and an ionizing dose of 0.66 MGy, including a safety factor of 1.5. Radiation-hard n+-in-p micro-strip sensors for use in the ITk have been developed by the ATLAS ITk Strip Sensor collaboration and produced by Hamamatsu Photonics K.K. In this paper, the results obtained from the electrical characterization of the latest barrel ATLAS17LS sensor prototype, before and after irradiation, are shown.
Surface properties of the long-strip barrel, full-sized and miniature sensors have been studied before and after proton, neutron and gamma irradiation up to the maximal fluences and radiation doses specified for the ITk Strip tracker. Sensors have been irradiated by protons at CYRIC, Tohoku University (Japan), the Proton Irradiation Facility at CERN, Karlsruhe Inst. Tech. (Germany) and at the University of Birmingham (UK), by neutrons from the Ljubljana TRIGA reactor (Slovenia) and by gamma rays from the 60Co source in UJP Praha (Czech Republic).
It has been verified that the surface radiation damage does not influence the sensor functionality. The breakdown voltage is well above the maximum operational voltage. All the tested surface parameters, such as the inter-strip resistance and capacitance, coupling capacitance and bias resistance satisfy the ATLAS ITk specifications for strip sensors.
A novel microstrip sensor geometry, the stereo annulus, has been developed for use in the end-cap of the ATLAS experiment’s strip tracker upgrade at the HL-LHC. Its first implementation is in the ...ATLAS12EC sensors, a large-area, radiation-hard, single-sided, AC-coupled, n+-in-p design produced by the ITk Strip Sensor Collaboration and fabricated by Hamamatsu Photonics in early 2017. The results of the initial testing of two ATLAS12EC batches are presented here with a comparison to specification. The potential of the new sensor shape to reinvigorate endcap strip tracking is explained and its effects on sensor performance are isolated by comparing the bulk mechanical and electrical properties of the new sensor to the previous iteration of prototype, the conventional barrel ATLAS12A sensor. The surface properties of the new sensor are evaluated for full-size unirradiated sensors as well as for mini sensors unirradiated and irradiated with protons up to a fluence of 2.2×1015neq cm−2. The results show that the new stereo annulus ATLAS12EC sensors exhibit excellent performance and the expected irradiation evolution.
The impact of uncontrolled urban growth (‘sprawl’) on air pollution and associated population exposure is investigated. This is done for the Ruhr area in Germany, by means of a coupled modelling ...system dealing with land use changes, traffic, meteorology, and atmospheric dispersion and chemistry. In a companion paper De Ridder, K., Lefebre F., Adriaensen S., Arnold U., Beckroege W., Bronner C., Damsgaard O., Dostal I., Dufek J., Hirsch J., Int Panis L., Kotek Z., Ramadier T., Thierry A., Vermoote S., Wania A., Weber C., 2008. Simulating the impact of urban sprawl on air quality and population exposure in the German Ruhr area. Part I: reproducing the base state., a description was given of the coupling of these models and of the validation of simulation results. In the present paper, a land use change scenario was implemented to mimic urban sprawl, relocating 12% of the urban population in the study domain to the green periphery. The resulting updated land use, population and employment density patterns were then used as input for traffic simulations, yielding an increase of total traffic volume by almost 17%. As a consequence, the domain-average simulated pollutant concentrations of ozone and particulate matter increased, though by a smaller amount, of approximately 4%. In a final step, population exposure to air pollution was calculated, both for the base case and the scenario simulations. A very slight domain-average exposure increase was found, of the order of a half percent. A compensating mechanism was identified, explaining this small figure. However, when stratifying the population into groups of individuals that were relocated to the urban periphery and those that were not, much larger exposure changes following urban sprawl emerged. Indeed, it was found that the relatively small proportion of relocated individuals benefited of a decrease of exposure to particulate matter by almost 13%, mainly because of their moving out of the most polluted areas; and that this came at the expense of an increase of exposure of 1.2% by the individuals not having moved.
The planned High Luminosity Large Hadron Collider is being designed to maximise the physics potential of the LHC with 10 years of operation at instantaneous luminosities of 7.5×1034cm−2s−1. A ...consequence of this increased luminosity is the expected radiation damage requiring the tracking detectors to withstand hadron fluence to over 1×1015 1 MeV neutron equivalent per cm2 in the ATLAS Strips system. Fast readout electronics, deploying 130 nm CMOS front-end electronics are glued on top of a silicon sensor to make a module. The radiation hard n-in-p micro-strip sensors used have been developed by the ATLAS ITk Strip Sensor collaboration and produced by Hamamatsu Photonics. A series of tests were performed at the DESY-II test beam facility to investigate the detailed performance of a strip module with both 2.5 cm and 5 cm length strips before irradiation. The DURANTA telescope was used to obtain a pointing resolution of 2 μm, with an additional pixel layer installed to improve timing resolution to ∼25 ns. Results show that prior to irradiation a wide range of thresholds (0.5–2.0 fC) meet the requirements of a noise occupancy less than 1×10−3 and a hit efficiency greater than 99%.
A novel microstrip sensor geometry, the stereo annulus, has been developed for use in the end-cap of the ATLAS experiment’s strip tracker upgrade at the HL-LHC. Its first implementation is in the ...ATLAS12EC sensors, a large-area, radiation-hard, single-sided, AC-coupled, n+ -in-p design produced by the ITk Strip Sensor Collaboration and fabricated by Hamamatsu Photonics in early 2017. The results of the initial testing of two ATLAS12EC batches are presented here with a comparison to specification. The potential of the new sensor shape to reinvigorate endcap strip tracking is explained and its effects on sensor performance are isolated by comparing the bulk mechanical and electrical properties of the new sensor to the previous iteration of prototype, the conventional barrel ATLAS12A sensor. The surface properties of the new sensor are evaluated for full-size unirradiated sensors as well as for mini sensors unirradiated and irradiated with protons up to a fluence of 2.2 x 1015 neq cm-2. The results show that the new stereo annulus ATLAS12EC sensors exhibit excellent performance and the expected irradiation evolution.
Compact city forms are associated with minimal consumption of land and energy, hence, they are often promoted as being the more sustainable thus preferred mode of urban development. In this context, ...numerical simulations were performed to evaluate the effect of urban sprawl on air quality and associated human exposure. Working on a highly urbanised area in the German Ruhrgebiet, models dealing with satellite data processing, traffic flows, pollutant emission and atmospheric dispersion were applied in an integrated fashion, under conditions representative of the urbanised area as it is today. A fair agreement was obtained between simulated and observed meteorological variables, as well as between simulated and observed concentrations of ozone and particulate matter. Simulated atmospheric pollution fields were found to closely reflect urbanisation patterns. In a companion paper De Ridder, K., Lefebre, F., Adriaensen, S., Arnold, U., Beckroege, W., Bronner, C., Damsgaard, O., Dostal, I., Dufek, J., Hirsch, J., IntPanis, L., Kotek, Z., Ramadier, T., Thierry, A., Vermoote, S., Wania, A., Weber, C., 2008. Simulating the impact of urban sprawl on air quality and population exposure in the German Ruhr area. Part II: Development and evaluation of an urban growth scenario, the results of this base case simulation will be compared with those of a scenario simulation, designed to mimic urban sprawl, so as to allow the evaluation of the latter on air quality and associated human exposure.
Mechanical properties of partially pyrolyzed at 650
°C or 750
°C unidirectional basalt fibre composites with polysiloxane matrix were studied at laboratory and elevated temperatures. Ten pyrolysis ...processes differing mutually in heating courses and ultimate temperatures were compared. The material treated at 650
°C revealed at laboratory temperature flexural strength around 850
MPa. Fracture toughness of this material exceeded that of the cured only (at 250
°C) and treated at 750
°C composites. However, the composite pyrolyzed at 750
°C is more suitable for applications at elevated temperatures because of its slower degradation in hot air.
A new macrocyclic DOTA-like ligand (BPAMD) for bone imaging and therapy containing a monoamide bis(phosphonic acid) bone-seeking group was designed and synthesized. Its lanthanide(III) complexes were ...prepared and characterized by 1H and 31P NMR spectroscopy. The Gd(III)−BPAMD complex was investigated in detail by 1H and 17O relaxometric studies to inspect parameters relevant for its potential application as an MRI contrast agent. Sorption experiments were conducted with Gd(III) and Tb(III) complexes using hydroxyapatite (HA) as a model of bone surface. Very effective uptake of the Gd−BPAMD complex by the HA surface was observed in NMR experiments. Radiochemical studies with the (160Tb−BPAMD)−HA system proved the sorption to be remarkably fast and strong on one hand and fully reversible on the other hand. The strong (Gd−BPAMD)−HA interaction was also supported by 1H NMRD measurements in the presence of a hydroxyapatite slurry, which showed an increase of the rotational correlation time upon adsorption of the complex on the HA surface, resulting in a significant relaxivity enhancement. The amide-bis(phosphonate) moiety is the only factor responsible for the binding of the complex to HA.
Food application of wheat B-starch comprising small starch granules as a result of lower quality is problematic. Accordingly, B-starch or acetylated starch prepared from it, with the degree of ...substitution (DS) of 1.5–2.3, was used in biodegradable films after blending with poly-(ε-caprolactone) (PCL). The following mechanical characteristics of the produced films were derived from the stress-strain curves: Young modulus, yield stress, stress-at-break, and strain-at-break. Water absorption of PCL/starch (60/40) films was determined according to European standard ISO 62. The measured data were compared with those of commercial A-starch. The films containing native starch degraded in compost totally during 2 months. Acetylation of starch molecules in the composites reduced the degradation rate. Optical microscopy, in combination with the image analysis system NIS-Elements vs. 2.10 completed with an Extended Depth of Focus (EDF) module, was used to study the surface morphology of PCL/starch films after 20-day and 42-day compost incubation. Chemical changes in the compost used for the film exposition were measured.
Native and acetylated B-starch was used in biodegradable films after blending with either poly-(ε-caprolactone) (PCL) or ethylene vinyl acetate copolymer (EVA). The following mechanical ...characteristics of prepared films were derived from the stress-strain curves: Young modulus, yield stress, stress-at-break and strain-at-break. Acetylation of starch molecules in the composites reduced the degradation rate in compost. Optical microscopy, combined with the image analysis system NIS-Elements completed with extended depth of focus (EDF) module, was used to study the PCL/starch and EVA/starch films surface morphology during composting. Parameters of the compost used for film exposition were measured.
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