5,573 research outputs found

    Beam Phase Monitor for CLIC and CTF3: pick-up design

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    presented at CLIC09 Workshop, 12-16 October 2009, CER

    Design and electromagnetic analysis of the new DAFNE interaction region

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    A new interaction region (IR) vacuum chamber has been designed for the DAFNE upgrade aimed at testing of the crabbed waist collision scheme. Compared to the existing IR vacuum chamber, the new one has a simplified design and consists essentially of the confluence of straight tubes, having a double Y shape. Sharp discontinuities have been avoided to limit the beam impedance of the structure. However, the study of the electromagnetic interaction with the beam is necessary in order to avoid excessive power loss due to possible higher order modes (HOM) trapped in the Y-shape chamber. The first design of the chamber has been analyzed with HFSS and HOMs have been found and characterized. On the basis of these results some modifications in the geometry of the IR chamber have been introduced to eliminate or attenuate these trapped resonances. The results of these simulations are presented. New electromagnetic shielding for the bellows inserted in the IR chambers, have been developed as well. The design criteria and the simulation results for these shielded bellows are also reported

    The SMILING project : prevention of falls by a mechatronic training device

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    Ageing is characterized by functional changes that can create gait and balance disturbances, which are the main risk factors of falling. Elderly people at risk of falling can be considered to be suffering from an involuntary motor behaviour that restricts their participation in society. One method to overcome such a situation is to activate a new learning process to train for real life tasks, which represents innovation. The SMILING system is intended to challenge the elderly to solve new problems in real time by inducing variable environments that need active response and problem solving. Variable environments induced by perturbations will weaken stiff motor behaviour(s), induce flexibility and thus enable effective training and improve mobility in real life environments. The SMILING solution provides a changeable yet safe environment that needs active response and problem solving by the user. It consists of a wearable non-invasive computer-controlled system that applies chaotic perturbations to the lower extremities during walking through small alterations of the height and slope of weight-bearing surfaces. The complete system consists of 3 modules: i) a complete walking analysis system; ii) a pair of motorised training shoes; iii) a user friendly portable control unit

    Organic enrichment can increase the impact of microplastics on meiofaunal assemblages in tropical beach systems

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    The cumulative impact of microplastic and organic enrichment is still largely unknown. Here, we investigated the microplastic contamination, the organic enrichment and their effects on meiofaunal distribution and diversity in two islands of the Maldivian archipelago: one more pristine, and another strongly anthropized. Field studies were coupled with manipulative experiments in which microplastic polymers were added to sediments from the non-anthropized island (i.e., without organic enrichment) to assess the relative effect of microplastic pollution on meiofauna assemblages. Our results reveal that the impact of microplastic contamination on meiofaunal abundance and taxa richness was more significant in the anthropized island, which was also characterized by a significant organic enrichment. Meiofauna exposed experimentally to microplastic contamination showed: i) the increased abundance of opportunistic nematodes and copepods and ii) a shift in the trophic structure, increasing relevance in epistrate-feeder nematodes. Based on all these results, we argue that the coexistence of chronic organic enrichment and microplastics can significantly increase the ecological impacts on meiofaunal assemblages. Since microplastic pollution in the oceans is predicted to increase in the next decades, its negative effects on benthic biodiversity and functioning of tropical ecosystems are expected to worsen especially when coupled with human-induced eutrophication. Urgent actions and management plans are needed to avoid the cumulative impact of microplastic and organic enrichment

    Commissioning Status of the CTF3 Delay Loop

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    The CLIC Test Facility CTF3, built at CERN by an international collaboration, aims at demonstrating the linear collider by 2010. In particular, one of the main goals is to study the generation of high-current electron pulses by interleaving bunch trains in delay lines and rings using transverse RF deflectors. This will be done in the 42 m long delay loop, built under the responsibility of INFN/LNF, and the 84 m long combiner ring that will follow it. The delay loop installation was completed and its commissioning started at the end of 2005. In this paper the commissioning results are presented, including the first tests of beam recombination

    Search for strange quark matter and Q-balls with the SLIM experiment

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    We report on the search for Strange Quark Matter (SQM) and charged Q-balls with the SLIM experiment at the Chacaltaya High Altitude Laboratory (5230 m a.s.l.) from 2001 to 2005. The SLIM experiment was a 427 m2^{2} array of Nuclear Track Detectors (NTDs) arranged in modules of 24×2424 \times 24 cm2^{2} area. SLIM NTDs were exposed to the cosmic radiation for 4.22 years after which they were brought back to the Bologna Laboratory where they were etched and analyzed. We estimate the properties and energy losses in matter of nuclearites (large SQM nuggets), strangelets (small charged SQM nuggets) and Q-balls; and discuss their detection with the SLIM experiment. The flux upper limits in the CR of such downgoing particles are at the level of 1.310151.3 10^{-15}/cm2^{2}/s/sr (90% CL).Comment: 4 pages, 7 eps figures. Talk given at the 24th International Conference on Nuclear Tracks in Solids, Bologna, Italy, 1-5 September 200

    High luminosity interaction region design for collisions inside high field detector solenoid

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    An innovatory interaction region has been recently conceived and realized on the Frascati DA{\Phi}NE lepton collider. The concept of tight focusing and small crossing angle adopted to achieve high luminosity in multibunch collisions has evolved towards enhanced beam focusing at the interaction point with large horizontal crossing angle, thanks to a new compensation mechanism for the beam-beam resonances. The novel configuration has been tested with a small detector without solenoidal field yielding a remarkable improvement in terms of peak as well as integrated luminosity. The high luminosity interaction region has now been modified to host a large detector with a strong solenoidal field which significantly perturbs the beam optics introducing new design challenges in terms of interaction region optics design, beam transverse coupling control and beam stay clear requirements. Interaction region design criteria as well as the luminosity results relevant to the structure test are presented and discussed.Comment: 12 pages, 9 figures, submitted to JINS
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