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

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

Design development and implementation of an irradiation station at the neutron time-of-flight facility at CERN

A new parasitic, mixed-field, neutron-dominated irradiation station has been recently commissioned at the European Laboratory for Particle Physics (CERN). The station is installed within the neutron time-of-flight (n_TOF) facility, taking advantage of the secondary radiation produced by the neutron spallation target, with neutrons ranging from 0.025 eV to several hundreds of MeV. The new station allows radiation damage studies to be performed in irradiation conditions that are closer to the ones encountered during the operation of particle accelerators; the irradiation tests carried out in the station will be complementary to the standard tests on materials, usually performed with gamma sources. Samples will be exposed to neutron-dominated doses in the MGy range per year, with minimal impact on the n_TOF facility operation. The station has 24 irradiation positions, each hosting up to 100 cm3 of sample material. In view of its proximity to the n_TOF target, inside protective shielding, the irradiation station and its operating procedures have been carefully developed taking into account the safety of personnel and to avoid any unwanted impact on the operation of the n_TOF facility and experiments. Due to the residual radioactivity of the whole area around the n_TOF target and of the irradiated samples, access to the irradiation station is forbidden to human operators even when the n_TOF facility is not in operation. Robots are used for the remote installation and retrieval of the samples, and other optimizations of the handling procedures were developed in compliance with radiation protection regulations and the aim of minimizing doses to personnel. The sample containers were designed to be radiation tolerant, compatible with remote handling, and subject to detailed risk analysis and testing during their development. The whole life cycle of the irradiated materials, including their post-irradiation examinations and final disposal, was considered and optimized

ATS Workshop 2024

As CERN operates its accelerator complex with a high-energy charged particle beam, the interaction of this beam with various systems designed to guide, shape, absorb and produce secondary particles, results in production of radioactive components and the activation of nearby equipment. Consequently, the components need to be safely managed and handled once they are removed from the accelerator complex, either to store or safely and sustainably dispose them as waste. Host-state requirements dictate the specific packaging type, size, composition, and activity levels that these packages shall have. Moreover, ALARA principles must be included in the design processes for new beam intercepting devices and target production areas, to reduce exposure of personnel to ionizing radiation and to optimally exploit these installations. The experience derives from both CERN internal expertise as well as from worldwide facilities and active collaboration. This presentation will discuss the experiences gained in the design, implementation, operation, and waste packaging of highly activated radioactive equipment under the responsibility of the CERN STI/TCD. Additionally, it will explain how these lessons learned are being incorporated into the design of new beam intercepting devices components and target stations

Robotics remote handling of a collimator

Open days activité robotique l'installation d'un collimateur en remot

Latest Advances in Targetry Systems at CERN and Exciting Avenues for Future Endeavours

CERN’s accelerator complex offers diverse target systems for a range of scientific pursuits, including varying beam energies, intensities, pulse lengths, and objectives. Future high-intensity fixed target experiments aim to advance this field further. This contribution highlights upgraded operational target systems, enhancing CERN’s physics endeavours. One example is the third-generation n_{T}OF spallation neutron target, using a nitrogen-cooled pure lead system impacted by a 20 GeV/c proton beam. Another focuses on recent antiproton production target upgrades, with a high-intensity 26 GeV/c beam colliding with a narrow-air-cooled iridium target. Looking ahead, new high-power target systems are planned. One aims to discover hidden particles using a 350-kW high-Z production target, while another enhances kaon physics through a 100 kW low-Z target. This article provides an overview of current target systems at CERN, detailing beam-intercepting devices and engineering aspects. It also previews upcoming facilities that could soon be implemented at CERN

How to Manage a Large Scale Beam Line Consolidation in a Highly Activated Area?

The TDC2/TCC2 consolidation is a good example showing how the complexity of interventions in high radiation areas has increased over the last five years. Due to its duration, its dispersion, the diversity of the teams involved, the fixed deadlines, the risks and external constraints, this worksite prefigures large scale-interventions in the LHC during long shutdown 2 (LS2) and even more LS3. The paper describes the three main project phases: preparation, execution (including monitoring and control) and closure emphasizing the indispensable steps in each stage. It also explains why integrating scope, schedule and dose into a single baseline is of prime importance and shows how to manage and monitor the radiation safety performance of the various interventions throughout the execution phase. Eventually, some recommendations are formulated in order to better accommodate the design of high radiation areas to their operation and maintenance constraints

Conical Targets for Enhanced High-Current Positron Sources

International audiencePrevious pair-production-driven positron source designs have assumed that the transverse dimension of the target is significantly greater than the secondary beam it generates. This paper explores the use of targets with different transverse profiles with the aim of enhancing positron production. The starting point of this research is the concept of wire targets, proposed by M. James et al. in 1991 for the former SLC positron source. Building on this foundation, this study takes this concept a step further by introducing conical-shaped targets, which can substantially improve the yield by reducing the reabsorption of positrons by the target--an issue that is worsened by the high-field solenoid lenses commonly used for positron capture. Using Geant4 simulations, we propose new conical targets adapted for the parameters of the future collider FCC-ee and its positron source test facility P-cubed (PSI Positron Production experiment) at the Paul Scherrer Institute. We find that conical targets can nearly double the positron production at the target and enhance the baseline positron yield of FCC-ee by around 60%. Additionally, we present the thermo-mechanical studies for the conical targets based on the FCC-ee primary beam power requirements and outline the mechanical implementation for a future proof-of-principle demonstration at the P-cubed facility

Les entreprises de biens de consommation sous l’Occupation

Ce volume prolonge l'histoire de la vie économique et des entreprises sous l'Occupation avec l'étude d'une nouvelle branche, les industries de consommation, entendues largement, de l'agro-alimentaire à l'automobile, en passant par le textile. Il s'inscrit également dans une historiographie des entreprises de biens de consommation en plein renouvellement depuis une décennie, qui s'intéresse autant à l'histoire industrielle et commerciale qu'à celle des attitudes des consommateurs. Le cadre retenu privilégie le point de vue de l'entreprise en étudiant à la fois les conditions de fabrication des biens de consommation et l'organisation des circuits de vente ; il ne néglige pas pour autant l'approche par les consommateurs. La vie des entreprises est marquée par des conditions d'approvisionnement difficiles, qui les obligent à recourir à des produits de remplacement. Comment parviennent-elles à échapper aux prélèvements de main d'œuvre et aux mesures de concentration ? Doivent-elles transformer leur production pour répondre aux exigences de l'occupant en particulier Dans quelle mesure réalisent-elles cependant des profits importants ? Autant de questions auxquelles cet ouvrage, qui s'appuie sur les recherches récentes des meilleurs spécialistes français et étrangers, s'efforce de répondre

Conceptual design of the SHiP Target and Target Complex

An introduction to the conceptual design of the SHiP facility production target and of the associated target comple