167 research outputs found
Conductor losses calculation in two-dimensional simulations of H-plane rectangular waveguides
This paper presents a novel numerical approach to simulate H-plane rectangular-waveguide microwave circuits considering a reduced quasi-2D simulation domain with benefits for computational cost and time. With the aim to evaluate the attenuation of the full height 3D component, we propose a modified expression for the waveguide top/bottom wall conductivity. Numerical 2D simulations are validated against results from full wave 3-D commercial electromagnetic simulator. After a benchmark on a simple straight waveguide model, the method has been successfully applied to an asymmetric un-balanced power splitter, where an accurate power loss prediction is mandatory. Simulation time and memory consumption can be reduced by a factor ten and seven respectively, in comparison with complete 3D geometries. Finally, we show that, also for quasi-2D E-bend waveguide, a case where the translational H-plane symmetry is broken, the error on conductor losses computation is mitigated by our approach since the method remains still valid in a first approximation
Mobile Daily Centre (Mdc) for Elder People with Cognitive Impairment: a Retrospective Observational Study
Introduction Trieste is a city characterized by a high mean age of the resident population, with 6,000 people with a cognitive impairment. Evidences show that is necessary to have a multidisciplinary approach, making alliances with the social network and families, while dealing with people with cognitive impairment. Because of this, the 3rd catchment district has developed a Mobile Daily Centre that aims to promote health, abilities and socialization giving the possibilities for these people to stay in a social context. Objectives Evaluating the impact of the Mobile Daily Centre on QoL of people with Cognitive Impairment. Aims Considering the rate of hospitalization and access to the first aid unit at the general hospital. Methods Retrospective Observational Study for the period between 01.01.2012 and 30.04.2014 on people in charge to the MDC. We have considered socio-demographic variables such as age, gender, care-givers; clinical variables such as psychopharmacotherapy and acetylcolinesterase-inhibitors drugs; rates of hospitalization, number of accesses to the first aid unit and of interventions of the MDC. Results in the period of the study 20 patients have been followed by the MDC; half of them had a psycho-pharmacological prescription. Very low rates of institutionalization have been detected. Conclusions MDC, in these small numbers, has shown to reduce the number of improper institutionalizations while guaranteeing to the elder people to maintain their abilities and socialization and to their care-givers periods of relief. Moreover, it promotes social inclusion and destigmatization. These results suggest that more territorial work and further studies should be done
The IsoDAR high intensity H2+ transport and injection tests
This technical report reviews the tests performed at the Best Cyclotron Systems, Inc. facility in regards to developing a cost effective ion source, beam line transport system, and acceleration system capable of high H[subscript 2][superscript +] current output for the IsoDAR (Isotope Decay At Rest) experiment. We begin by outlining the requirements for the IsoDAR experiment then provide overviews of the Versatile Ion Source (VIS), Low Energy Beam Transport (LEBT) system, spiral inflector, and cyclotron. The experimental measurements are then discussed and the results are compared with a thorough set of simulation studies. Of particular importance we note that the VIS proved to be a reliable ion source capable of generating a large amount of H[subscript 2][superscript +] current. The results suggest that with further upgrades, the VIS could potentially be a suitable candidate for IsoDAR. The conclusion outlines the key results from our tests and introduces the forthcoming work this technical report has motivated.National Science Foundation (U.S.) (PHY-1148134)Massachusetts Institute of Technology (Seed Fund)Massachusetts Institute of Technology (Bose Fellowship
Production of intense highly charged ion beams with SERSE
The source SERSE is operational at LNS since June 1998 and many improvements have been carried out in this period. The frequency has been increased from 14.5 GHz to 18 GHz and the use of two frequency heating has given positive results. Metallic ion production has been tested by means of a high temperature oven and the preliminary results are described. Tests of magnetic field scaling and frequency scaling have confirmed the results of previous tests with SC-ECRIS at lower frequency and seems to suggest that the upgrading of the source to higher frequency may be considered
A TM01 mode launcher with quadrupole field components cancellation for high brightness applications
The R&D of high gradient radiofrequency (RF) devices is aimed to develop innovative accelerating structures based on new manufacturing techniques and materials in order to construct devices operating with the highest accelerating gradient. Recent studies have shown a large increase in the maximum sustained RF surface electric fields in copper structures operating at cryogenic temperatures. These novel approaches allow significant performance improvements of RF photoinjectors. Indeed the operation at high surface fields results in considerable increase of electron beam brilliance. This increased brilliance requires high field quality in the RF photoinjector and specifically in its power coupler. In this work we present a novel power coupler for the RF photoinjector. The coupler is a compact X-band TM01 mode launcher with a fourfold symmetry which minimized both the dipole and the quadrupole RF components
ANOTHER PECULIAR SITUATION FOR YOY OF BLUEFIN TUNA (THUNNUS THYNNUS) IN THE MEDITERRANEAN SEA IN 2016
The possible effects of the hottest temperatures recorded in 2016 (the hottest so far) on the bluefin
tuna reproductive biology have been discussed by the SCRS in the past, but the situation in 2016
was very different. After collecting some detailed samples and data about the presence of YOY in
various parts of the Mediterranean Sea, an unusual situation can be observed, showing different
size-at-time by area in late summer-fall 2016, possibly mirroring early, late, fractioned and
continued spawnings and different growth rates. These fish might result in future problems for
age readings and ALK at least for the juveniles of bluefin tunas born in 2016. This paper provides
the growth curves for the many cohorts of bluefin tuna YOY which have been detected and that
were born in 2016
Status of the light ion source developments at CEA/Saclay
ACC NIMInternational audienceSILHI (High Intensity Light Ion Source) is an ECR ion source producing high intensity proton ordeuteron beams at 95 keV. It is now installed in the IPHI site building, on the CEA/Saclay center. IPHI is a frontend demonstrator of high power accelerator. The source regularly delivers more than 130 mA protons in CWmode and already produced more than 170 mA deuterons in pulsed mode at nominal energy. The last beamcharacterisations, including emittance measurements, space charge compensation analysis and diagnosticimprovements, will be reported. Taking into account the SILHI experience, new developments are in progress tobuild and test a 5 mA deuteron source working in CW mode. This new source will also operate at 2.45 GHz andpermanent magnets will provide the magnetic configuration. This source, of which the design will be discussed,will have to fit in with the SPIRAL 2 accelerator developed at GANIL to produce Radioactive Ion Beams. TheH- test stand status is briefly presented here and detailed in companion papers.This work is partly supported by the European Commission under contract n°: HPRI-CT-2001-50021
High Current, High frequency ECRIS development program for LHC heavy ion beam application
A research program with the aim of producing pulsed currents with hitherto unequalled intensity of Pb27+, with length and repetition ratecompatible with those desired by CERN (1 mAe / 400 ms / 10 Hz in the context of future heavy ion collisions at LHC) is organised in acollaboration between CERN/GSI/CEA-Grenoble and IN2P3-ISNG.Two main experimental programs will be carried out : (i) tests with the LNS-Catania team on the SERSE superconducting source with a 28 GHzgyrotron, (ii) tests on a non-superconducting source (new source at Grenoble) with a 28 GHz gyrotron. For this purpose CEA/DRFMC hasborrowed from CEA a 28 GHz - 10 kW gyrotron transmitter.The project includes also the construction of a source body, by ISNG, with conventional coils and permanent magnets for working at the frequencyof about 28 GHz and biased up to 60 kV. This source called PHOENIX will run on a test bench at ISN. PHOENIX is an improvement of thepresent ECR4-14.5 GHz/CERN source, having a mirror ratio R=2 at 14.5 GHz, and R=1.7 at 28 GHz (possibly reaching 2.1 T on the axis of thesource), and with a plasma volume up to 2.5 larger.Experiments at 28 GHz will be performed on the SERSE source in Catania at INFN/LNS where both the axial and the hexapolar fields will bevaried so that the mirror ratio is continuously varied up to R=1.6 ; the SERSE source will be also operated at lower magnetic fields such as thosewhich can be produced by conventional magnets (less than 2 T axial field at injection - far from the 28 GHz High-B mode)
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