208 research outputs found
Fabrication and Results of the First MgB2 Round Coil Superferric Magnet at LASA
The LASA Laboratory (INFN, Milan) is working in the High Luminosity LHC program to develop, in collaboration with CERN, six different types of High Order corrector magnets. In this framework, in parallel with a conventional design of superferric magnets with LTS conductor, the LASA is focusing on the research of new superconducting materials which may have applications in particle accelerator magnets. To this purpose, LASA is developing a new type of superferric magnet suitable to arbitrary multipole order, called Round Coil Superferric Magnets (RCSM). The iron yoke shaped with an arbitrary number of poles is able to create the desired harmonic component using only one single round coil with a large bending radius suitable for very strain-sensitive superconductors. The electromagnetic design of a sextupole configuration of the magnet and the production of the first superconducting MgB2 round coil prototype have been already presented. In this paper, we expose the optimization of the iron yoke and polar expansions assembly of the first magnet semi-module prototype. The results of the whole powering test are described in detail and the analysis of the magnetic performances are compared with those of classical superferric correctors
Nanostructured Europium Oxide thin films deposited by pulsed laser ablation of a metallic target in a He buffer atmosphere
Nanostrucured Europium oxide and hydroxide films were obtained by pulsed
Nd:Yag (532 nm) laser ablation of an Europium metallic target, in the presence
of a 1 mbar Helium buffer atmosphere. Both the produced film and the ambient
plasma were characterized. The plasma was monitored by an electrostatic probe,
for plume expansion in vacuum or in the presence of the buffer atmosphere. The
time evolution of the ion saturation current was obtained for several probe to
substrate distances. The results show the splitting of the plume into two
velocity groups, being the lower velocity profile associated with metal cluster
formation within the plume. The films were obtained in the presence of helium
atmosphere, for several target to substrate distances. They were analyzed by
Rutherford backscattering spectrometry (RBS), X-Ray Diffraction (XRD) and
Atomic Force Microscopy, for samples as-deposited and treated at 600 degrees C
in air. The results show that the as-deposited samples are amorphous and have
chemical composition compatible with Europium hydroxide. The thermally treated
samples show X-Ray diffraction peaks of Eu_2O_3, with chemical composition
showing excess oxygen. Film nanostructuring was shown to be strongly correlated
to cluster formation, as shown by velocity splitting in probe current versus
time plots.Comment: 7 pages, 11 figures, 31 reference
Making space for shellfish farming along the Adriatic coast
This work focuses on the selection of new areas for shellfish farming along the coast of the Northern Adriatic Sea (Italy). Shellfish site suitability was assessed by means of a methodology based on Spatial Multi-Criteria Evaluation (SMCE), which provided the framework to combine mathematical models and operational oceanography products. Intermediate level criteria considered in the analysis included optimal growth conditions, environmental interactions, and socio-economic evaluation (e.g. organic carbon deposition; distance to harbour). Results showed that the whole coastal area comprised within 0 and 3 nm is highly suitable for farming of mussel, while the area comprised between 3 and 12 nm is divided between a highly suitable northern part, and a less suitable southern one. Seven different scenarios of development of shellfish aquaculture industry were explored. The introduction of a new species, and the assessment of the exposure to storm events are specific aspects taken into account in development scenarios. Results show that the degree of suitability for shellfish aquaculture in this area would not change dramatically with the introduction of oyster farming. Furthermore, results highlight that: (i) the growth potential in this area is high; (ii) the space with suitability index >0.5 increases when prioritizing the optimal growth condition criteria, and (iii) the socio-economic is the most restrictive Intermediate Level Criteria. Results were discussed by deriving general lessons concerning the use of SMCE in aquaculture space allocation, from the specific application in the Northern Adriatic Sea. Challenges and opportunities related to the proposed methodological framework, with particular reference to the use of resources provided by remote sensing and operational oceanography by means of mathematical models, were also discussed. Results can support a science-based identification of allocated zones for aquaculture in order to avoid conflicts, and promote sustainable aquaculture in the Mediterranean Sea, where the space for these activities is becoming increasingly limited
A Work Proposal for a Collaborative Study of Magnet Technology for a Future Muon Collider
In this paper we elaborate on the nature and challenges for the magnet
systems of a muon collider as presently considered within the scope of the
International Muon Collider Collaboration (IMCC). We outline the structure of
the work proposed over the coming period of five years to study and demonstrate
relevant magnet technology. The proposal, which is part of the overall work
planned to establish feasibility of a muon collider, is in direct response to
the recent recommendations received from the Laboratories Directors Group
(LDG). The plan is to profit from joint activities, within the scope of the
IMCC and beyond, implemented through direct and EU-funded contributions.Comment: contribution to Snowmass 202
Assessment of atrial regional and global electromechanical function by tissue velocity echocardiography: a feasibility study on healthy individuals
BACKGROUND: The appropriate evaluation of atrial electrical function is only possible by means of invasive electrophysiology techniques, which are expensive and therefore not suitable for widespread use. Mechanical atrial function is mainly determined from atrial volumes and volume-derived indices that are load-dependent, time-consuming and difficult to reproduce because they are observer-dependent. AIMS: To assess the feasibility of tissue velocity echocardiography (TVE) to evaluate atrial electromechanical function in young, healthy volunteers. SUBJECTS AND METHODS: We studied 37 healthy individuals: 28 men and nine women with a mean age of 29 years (range 20–47). Standard two-dimensional (2-D) and Doppler echocardiograms with superimposed TVE images were performed. Standard echocardiographic images were digitized during three consecutive cardiac cycles in cine-loop format for off-line analysis. Several indices of regional atrial electrical and mechanical function were derived from both 2-D and TVE modalities. RESULTS: Some TVE-derived variables indirectly reflected the atrial electrical activation that follows the known activation process as revealed by invasive electrophysiology. Regionally, the atrium shows an upward movement of its walls at the region near the atrio-ventricular ring with a reduction of this movement towards the upper levels of the atrial walls. The atrial mechanical function as assessed by several TVE-derived indices was quite similar in all left atrium (LA) walls. However, all such indices were higher in the right (RA) than the LA. There were no correlations between the 2-D- and TVE-derived variables expressing atrial mechanical function. Values of measurement error and repeatability were good for atrial mechanical function, but only acceptable for atrial electrical function. CONCLUSION: TVE may provide a simple, easy to obtain, reproducible, repeatable and potentially clinically useful tool for quantifying atrial electromechanical function
A Muon Collider Facility for Physics Discovery
Muon colliders provide a unique route to deliver high energy collisions thatenable discovery searches and precision measurements to extend ourunderstanding of the fundamental laws of physics. The muon collider design aimsto deliver physics reach at the highest energies with costs, power consumptionand on a time scale that may prove favorable relative to other proposedfacilities. In this context, a new international collaboration has formed tofurther extend the design concepts and performance studies of such a machine.This effort is focused on delivering the elements of a 10 TeV center ofmass (CM) energy design to explore the physics energy frontier. The path tosuch a machine may pass through lower energy options. Currently a 3 TeV CMstage is considered. Other energy stages could also be explored, e.g. ans-channel Higgs Factory operating at 125 GeV CM. We describe the status of theR&D and design effort towards such a machine and lay out a plan to bring theseconcepts to maturity as a tool for the high energy physics community.<br
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