9 research outputs found

    Equipment for tunnel installation of main and insertion LHC cryo-magnet

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    The installation of about 1700 superconducting dipoles and quadrupoles in the Large Hadron Collider (LHC) is now well underway. The transport and installation of the LHC cryo-magnets in the LEP tunnels originally designed for smaller, lighter LEP magnets have required development of completely new handling solutions. The severe space constraints combined with the long, heavy loads have meant that solutions had to be very sophisticated. The paper describes the procedure of the installation of the main cryo-magnets in the arc as well as the more specific insertion cryo-magnets. The logistics for the handling and transport are monitored with tri-axial acceleration monitoring devices that are installed on each cryo-magnet to ensure their mechanical and geometric integrity. These dynamic results are commented. The paper includes conclusions and some lessons learne

    Installation of the LHC Long Straight Sections (LSS)

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    The LHC long straight sections (LSS) serve as experimental or utility insertions. There are two high luminosity experimental insertions located at points 1 and 5 and two more experimental insertions at points 2 and 8 which also contain the injection systems. The beams only cross at these four locations and are focused by superconducting low-beta triplets. Insertions 3 and 7 each contain two collimation systems. Insertion 4 contains two RF systems. Insertion 6 contains the beam dumping system. The installation of the LSS is a challenge due to the compact layout that characterises these areas and the difficulties related to the underground work mainly in zones of restricted access. Specific devices are required for handling and installing various heavy and voluminous elements. This paper reviews the installation scenarios, describes the sequences presently planned and highlights the potential problem areas. The particular case of sector 7-8 where the LSS elements will be installed in parallel with the cryogenic distribution line (QRL) is used as an example of a 'rapid' installation scheme to illustrate how resources are used. The consequences of possible shortcuts are also mentioned

    Configuration Management Best Practices

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    Configuration management (CM) is used for the configuration of complex systems in many fields, such as IT, aeronautics, shipbuilding, space systems, nuclear power plants, etc. and is indispensable for the long-term operation of any large facility. In the Engineering Department, configuration management consists of managing the technical description and layout of the accelerators and transfer lines (and their various components), as well as managing all the modifications made during their evolution over time. It is about all the processes that ensure the conformity of the accelerators with the requirements of their operation, throughout their life cycle. The aim is to provide a clear and coherent representation of the CERN main technical facilities at a given point in time. This paper will present, the best practices that constitute the configuration management of accelerators and transfer lines in the EN-ACE group

    HL-LHC Alignment Requirements and Associated Solutions

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    To increase by more than 10 times the luminosity reach w.r.t the first 10 years of the LHC lifetime, the HL-LHC project will replace nearly 1.2 km of the accelerator during the Long Shutdown 3 scheduled in 2024 [1][2][3]. This paper presents the HL-LHC alignment and internal metrology requirements of all the new components to be installed, from the magnet components to the beam instrumentation and vacuum devices. As for the LHC, a combination of Hydrostatic Levelling Sensors (HLS) and Wire Positioning Sensors (WPS) is proposed for the alignment of the main components, but on a longer distance (210 m instead of 50 m), generating technical challenges for the installation of the stretched wire and for the maintenance of the alignment systems. Innovative measurements methods and instrumentation are under study to perform the position monitoring inside a cryostat of cold masses and crab cavities, in a cold (2K) and radioactive (1 MGy/year) environment, as well as to carry remote measurements in the tunnel of the intermediary components. The proposed solutions concerning the determination of the position and the re-adjustment of the components are detailed in this paper

    CERN Accelerators Topology Configuration: Facing the Next Long Shutdown

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    The Configuration and Layout (CL) team at CERN ensures that there is a clear and coherent representation of the status of the CERN underground facilities (about 60 km of equipment) and main accelerator projects at a given point in time. In view of the major equipment changes to be carried out during the extended end of year technical stop (EYETS), the next Long Shutdown (LS2), and to facilitate the associated preparatory work of multiple CERN groups, the CL team has developed an immersive visualisation tool, displaying 360 degree panoramic images of CERN underground facilities. In addition, the CL team is launching a process to manage future layout configurations inside the CERN Layout database in parallel to the current configuration. This paper presents the 360 degree panorama visualisation tool and the parallel configuration process, to view the past, current and future status of the CERN accelerator complex. It highlights their added value for the CERN groups in the preparatory phase for upgrade and consolidation modifications and discusses the potential future improvements

    Integration, Configuration and Coordination: from Project to Reality, at CERN

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    The rigorous process in place at CERN to approve and follow-up the implementation of any modification of the LHC machine and its Injectors is presented in this paper. Our methodology implies the support of three teams, in charge of the configuration management, the scheduling and safety coordination, and the 3D integration studies. At each stage of the project the support of the three teams evolves, to provide the adequate support in the preparation phase and during the technical stops and long shutdowns. The formal roles and the processes used to govern the interaction of the Integration, Configuration and Coordination teams, and their relation to the project teams during the preparation and implementation phases, for activities to be performed in LHC and its injector chain are described and discussed

    Global attitudes in the management of acute appendicitis during COVID-19 pandemic: ACIE Appy Study

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    Background: Surgical strategies are being adapted to face the COVID-19 pandemic. Recommendations on the management of acute appendicitis have been based on expert opinion, but very little evidence is available. This study addressed that dearth with a snapshot of worldwide approaches to appendicitis. Methods: The Association of Italian Surgeons in Europe designed an online survey to assess the current attitude of surgeons globally regarding the management of patients with acute appendicitis during the pandemic. Questions were divided into baseline information, hospital organization and screening, personal protective equipment, management and surgical approach, and patient presentation before versus during the pandemic. Results: Of 744 answers, 709 (from 66 countries) were complete and were included in the analysis. Most hospitals were treating both patients with and those without COVID. There was variation in screening indications and modality used, with chest X-ray plus molecular testing (PCR) being the commonest (19\ub78 per cent). Conservative management of complicated and uncomplicated appendicitis was used by 6\ub76 and 2\ub74 per cent respectively before, but 23\ub77 and 5\ub73 per cent, during the pandemic (both P < 0\ub7001). One-third changed their approach from laparoscopic to open surgery owing to the popular (but evidence-lacking) advice from expert groups during the initial phase of the pandemic. No agreement on how to filter surgical smoke plume during laparoscopy was identified. There was an overall reduction in the number of patients admitted with appendicitis and one-third felt that patients who did present had more severe appendicitis than they usually observe. Conclusion: Conservative management of mild appendicitis has been possible during the pandemic. The fact that some surgeons switched to open appendicectomy may reflect the poor guidelines that emanated in the early phase of SARS-CoV-2

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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