230 research outputs found

    Proposal to Increase the LEP Energy with Horizontal Orbit Correctors

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    In an e+ e- collider the beam energy depends only on the bending field integral "Bds while the synchrotron radiation power scales with "B2ds and is sensitive to the details of the field distribution. With fixed RF acceleration voltage it is thus possible to attain higher energies by increasing the effective bending magnet length. We propose to use the horizontal orbit correctors to exploit this effect. To control the orbit perturbations, 79 unused correctors in the regular arcs and 14 unused correctors in the dispersion suppressors will have to be powered. An energy increase of approximatively 0.18 GeV per beam might be obtained

    Rejets radioactifs et environnement du CERN en 2003

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    La radioactivitĂ© de l’environnement autour de l’Organisation EuropĂ©enne pour la Recherche NuclĂ©aire (CERN) et les doses de rayonnements qui en rĂ©sultent pour la population avoisinante sont contrĂŽlĂ©es par la Commission de SĂ»retĂ© du CERN et de maniĂšre indĂ©pendante par les autoritĂ©s compĂ©tentes des deux Etats HĂŽtes, l’Institut de Radioprotection et de SĂ»retĂ© NuclĂ©aire (IRSN) cĂŽtĂ© France et l’Office FĂ©dĂ©ral de la SantĂ© Publique (OFSP) cĂŽtĂ© Suisse. Dans ce rapport, les rĂ©sultats de mesures concernent en particulier le territoire suisse. L’ensemble des mesures effectuĂ©es en 2003 prouve que le fonctionnement des installations du CERN Ă©tait sans consĂ©quence radiologique sur l’environnement et la population. Le contrĂŽle des Ă©missions montre que les rejets effectifs se situent Ă©galement en 2003 nettement en dessous des limites rĂ©glementaires. Ce constat est confirmĂ© par le contrĂŽle des immissions dans l’environnement. Le CERN a bien respectĂ© en 2003 comme dans les annĂ©es prĂ©cĂ©dentes la valeur directrice de dose liĂ©e Ă  la source fixĂ©e Ă  0.3 mSv/an. L’impact rĂ©el reprĂ©sente en fait moins de 10% de cette valeur, comme l’indique l’estimation pour le groupe critique, qui est de l’ordre de 0.03 mSv/an

    Physical and rehabilitation medicine (PRM) care pathways: Adults with severe traumatic brain injury

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    AbstractThis document is part of a series of guidelines documents designed by the French Physical and Rehabilitation Medicine Society (SOFMER) and the French Federation of PRM (FEDMER). These reference documents focus on a particular pathology (here patients with severe TBI). They describe for each given pathology patients’ clinical and social needs, PRM care objectives and necessary human and material resources of the pathology-dedicated pathway. ‘Care pathways in PRM’ is therefore a short document designed to enable readers (physician, decision-maker, administrator, lawyer, finance manager) to have a global understanding of available therapeutic care structures, organization and economic needs for patients’ optimal care and follow-up. After a severe traumatic brain injury, patients might be divided into three categories according to impairment's severity, to early outcomes in the intensive care unit and to functional prognosis. Each category is considered in line with six identical parameters used in the International Classification of Functioning, Disability and Health (World Health Organization), focusing thereafter on personal and environmental factors liable to affect the patients’ needs

    Dynamic beam based calibration of orbit monitors at LEP

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    The offsets of the beam position monitors (BOM) with respect to the centre of the quadrupoles were determined for 16 wide band electronic and 18 narrow band electronic monitors. The first are located near to the IPs and the latter are in all other parts. The distribution of the wide band monitor offsets at the low beta focusing quadrupole magnets has a mean value of 1000 ”m and a width of s = 600 mm. The offsets are almost identical with the beam position of the orbit which allows to obtain highest luminosity. The distribution of the narrow band monitor offsets has a mean value of 19 mm and a width of s = 245 mm

    ELENA, a preliminary cost and feasibility study

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    To produce dense pbar beams at very low energies (100-200 keV), a small decelerator ring could be built and installed between the existing AD ring and the experimental area. Phase-space blowup during deceleration would be compensated by electron cooling in order to obtain final emittances comparable to the 5MeV beam presently delivered by the AD. This report describes preliminary machine parameters and layout of ELENA and also gives an approximate estimate of cost and manpower needs

    IONS FOR LHC: STATUS OF THE INJECTOR CHAIN

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    The LHC will, in addition to proton runs, be operated with Pb ions and provide collisions at energies of 5.5 TeV per nucleon pair, i.e. more than 1.1 PeV per event, to experiments. The transformation of CERN's ion injector complex (Linac3-LEIR-PS-SPS) to allow collision of ions in LHC in 2008 is well under way. The status of these modifications and the latest results of commissioning will be presented. The remaining challenges are reviewed

    The CERN PS multi-turn extraction based on beam splittting in stable islands of transverse phase space: Design Report

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    Since 2001 considerable effort has been devoted to the study of a possible replacement of the continuous-transfer extraction mode from the PS to the SPS. Such an approach, called Multi-Turn Extraction (MTE), is based on capture of the beam inside stable islands of transverse phase space, generated by sextupoles and octupoles, thanks to a properly chosen tune variation. Both numerical simulations and measurements with beam were performed to understand the properties of this new extraction mode. The experimental study was completed at the end of 2004 and by the end of 2005 a scheme to implement this novel approach in the PS machine was defined and its performance assessed. This design report presents the outcome of the studies undertaken both in terms of technical issues as well as of resources necessary to implement the proposed scheme

    The energy calibration of LEP in the 1993 scan

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    This report summarizes the procedure for providing the absolute energy calibration of the LEP beams during the energy scan in 1993. The average beam energy around the LEP ring was measured in 25 calibrations with the resonant depolarization technique. The time variation of this average beam energy is well described by a model of the accelerator based on monitored quantities. The absolute calibration of the centre of mass energies of the off-peak points is determined with a precision of 2 parts in 10(5) resulting in a systematic error on the Z-mass of about 1.4 MeV and on the Z-width of about 1.5 MeV

    A Conditional Zebrafish MITF Mutation Reveals MITF Levels Are Critical for Melanoma Promotion vs. Regression In Vivo

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    The microphthalmia-associated transcription factor (MITF) is the “master melanocyte transcription factor” with a complex role in melanoma. MITF protein levels vary between and within clinical specimens, and amplifications and gain- and loss-of-function mutations have been identified in melanoma. How MITF functions in melanoma development and the effects of targeting MITF in vivo are unknown because MITF levels have not been directly tested in a genetic animal model. Here, we use a temperature-sensitive mitf zebrafish mutant to conditionally control endogenous MITF activity. We show that low levels of endogenous MITF activity are oncogenic with BRAFV600E to promote melanoma that reflects the pathology of the human disease. Remarkably, abrogating MITF activity in BRAFV600Emitf melanoma leads to dramatic tumor regression marked by melanophage infiltration and increased apoptosis. These studies are significant because they show that targeting MITF activity is a potent antitumor mechanism, but also show that caution is required because low levels of wild-type MITF activity are oncogenic
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