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The HL-LHC technical infrastructure includes the civil engineering, the electrical distribution, the cooling & ventilation, the access & alarm system, the technical monitoring, the transport, the logistics, the storage, and the operational safety., CERN Yellow Reports: Monographs, Vol. 10 (2020): High-Luminosity Large Hadron Collider (HL-LHC): Technical design report

The HL-LHC technical infrastructure includes the civil engineering, the electrical distribution, the cooling & ventilation, the access & alarm system, the technical monitoring, the transport, the logistics, the storage, and the operational safety.

The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up anew energy frontier for exploration in 2010, it has gathered a global user community of about 9000 scientists working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will need a major upgrade in the 2020s. This will increase its instantaneous luminosity (rate of collisions) by a factor of five beyond the original design valueand the integrated luminosity (totalnumber of collisions) by a factor ten. The LHC is already a highly complexand exquisitely optimised machine so this upgrade must be carefully conceived and will require new infrastructures(underground and on surface)and over a decade to implement. The new configuration, known as High Luminosity LHC (HL-LHC), relies on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11–12Tesla superconducting magnets, compact superconducting cavities for beam rotation with ultra-precise phase control, new technology and physical processes for beam collimation and 100 metre-long high-power superconducting links with negligible energy dissipation, all of which required several years of dedicated R&D; effort on a global international level. The present document describes the technologies and components that will be used to realise the projectand is intended to serve as the basis for the detailed engineering design of the HL-LHC.

So far, most potential applications of genomic prediction in plant improvement have been explored using cross validation approaches. This is the first empirical study to evaluate the accuracy of genomic prediction of the performances of progenies in a typical rice breeding program. Using a cross validation approach, we first analyzed the effects of marker selection and statistical methods on the accuracy of prediction of three different heritability traits in a reference population (RP) of 284 inbred accessions. Next, we investigated the size and the degree of relatedness with the progeny population (PP) of sub-sets of the RP that maximize the accuracy of prediction of phenotype across generations, i.e., for 97 F5–F7 lines derived from biparental crosses between 31 accessions of the RP. The extent of linkage disequilibrium was high (r2 = 0.2 at 0.80 Mb in RP and at 1.1 Mb in PP). Consequently, average marker density above one per 22 kb did not improve the accuracy of predictions in the RP. The accuracy of progeny prediction varied greatly depending on the composition of the training set, the trait, LD and minor allele frequency. The highest accuracy achieved for each trait exceeded 0.50 and was only slightly below the accuracy achieved by cross validation in the RP. Our results thus show that relatively high accuracy (0.41–0.54) can be achieved using only a rather small share of the RP, most related to the PP, as the training set. The practical implications of these results for rice breeding programs are discussed.

Recently, the conjunction of high-throughput marker technologies and new statistical methods has given birth to a new breeding strategy called genomic selection(GS).It refers to methods that use genome-wide dense marker genotyping for the prediction of genetic values with enough accuracy to allow selection based on that prediction alone. It consists of two steps: estimation of SNP effects within a training population (TP), and prediction of genomic estimated breeding values (GEBV) in the candidate population(CP)based on SNP genotypes. We present here GS for water use efficiency in rice, in the framework of a pedigree breeding scheme. The TP was composed of 284 accessions belonging to the temperate japonica and tropical japonica rice groups. The CP was composed of 99 F5-F7 lines derived from 36crosses involving 32 accessions of TP. The two populations were genotyped with an average marker density of 4.8perkb, with minimum minor allele frequency of 2.5.Phenotypic traits considered included flowering time (FL), grain yield (GY) and nitrogen balance index (NI)under conventional irrigation (CI) and aerobicsystem (AS).Phenotypes were modeled using two statistical regression methods: genomic best linear unbiased prediction (GBLUP) and reproducing kernel Hilbert Space (RKHS).The models were tested with three incidence matrixes corresponding to densities of 4.8, 9.5 and 13.8marker per kb, and to linkage disequilibrium (LD)thresholds of r²≤1, r²

CERN’s Linac2 currently injects protons with a kinetic energy of 50 MeV into the PS Booster (PSB). Linac2 will be replaced by Linac4 which will inject H$^-$ ions with a kinetic energy of 160 MeV into the PSB. In order to enable the PSB for charge-exchange injection, it will be equipped with a new injection system. The proposed charge-exchange injection system will use carbon foils (one for each of the four PSB rings) to remove the electrons from the H$^-$ ions. The remaining protons will then be merged with the already circulating proton beam. Two percent of the injected beam are expected to be either incompletely stripped or unstripped, and will be sent to 4 internal $\rm{H}^0/H^-$ injection dumps (one per PSB ring). This paper focuses on the induced activation in the future injection region. The radiological impact of proposed material choices for the internal dumps has been assessed by establishing Work and Dose Plannings for the most important foreseen interventions. The expected ambient dose equivalent rates at the various work locations have been obtained by FLUKA Monte Carlo simulations. In addition, the activation of the carbon foils and the derived need of protection measures during foil exchanges are discussed.

During the commissioning phase of the PS Multi-Turn Extraction (MTE) and the following operational period a number of limitations were observed, namely activation of the magnetic septum in straight section 16, fluctuation of the fraction of particles trapped in the islands, and instabilities of the injection trajectories in the SPS. These issues have been addressed in many ways, by either dedicated measurement campaigns or paper studies to determine mitigation measures. In this document the proposed solution of installing a dummy septum in straight section 15 of the PS ring to reduce the activation of the extraction magnetic septum is described in details.

The CERN PS Booster (PSB) is presently undergoing an ambitious consolidation and upgrade program within the frame of the LHC Injectors Upgrade (LIU) project. This program comprises a new injection scheme for H- ions from CERN’s new Linac4, the replacement of the main RF systems and an energy upgrade of the PSB rings from 1.4 to 2 GeV which includes the replacement of the main magnet power supply as well as the upgrade of the extraction equipment. This paper describes the status and plans of this work program.

CERN’s LHC injector chain will have to deliver beams with ultimate brilliance as the LHC is heading for increased luminosity in the coming years. In order to overcome bottlenecks in the injector chain, an increase of the beam transfer energy from the CERN Proton Synchrotron Booster (PSB) to the Proton Synchrotron (PS) has been investigated as a possible upgrade scenario. This paper gives an overview of the technical solutions and summarizes the conclusions of the feasibility study.

Personnel access to the LHC tunnel will be restricted to varying extents during the life of the machine due to radiation and cryogenic hazards. For this reason a remotely operated modular inspection train, (TIM) running on the LHC tunnel’s overhead monorail has been developed. In order to be compatible with the LHC personnel access system, a small section train that can pass through small openings at the top of sector doors has now been produced. The basic train can be used for remote visual inspection; additional modules give the capability of carrying out remote measurement of radiation levels, environmental conditions around the tunnel, and even remote measurement of the precise position of machine elements such as collimators. The paper outlines the design, development and operation of the equipment including preparation of the infrastructure. Key features of the trains are described along with future developments and intervention scenarios.

This paper describes methodology and findings of the Caribbean Pathway Analysis, a collaboration between the Caribbean Invasive Species Working Group (CISWG) and the United States Department of Agriculture, Plant Protection and Quarantine (USDA-PPQ). The objective of this study was to contribute to an improved understanding of pathways of plant pest movement into and within the Greater Caribbean Region (GCR), thereby helping CISWG to enhance its Caribbean Regional Invasive Species Intervention Strategy (CRISIS) for preventing the introduction and spread of exotic pests. The pathways investigated in this study were: human movement, airline passenger baggage, international mail, maritime traffic, hitchhikers, wood packaging material, forestry, propagative materials, and natural spread. The relative importance of each pathway as a source of pest introduction was rated. The pest risk associated with human movement, hitchhikers, wood packaging materials, forestry, and propagative materials was rated as very high. The pest risk associated with airline passenger baggage, mail, and natural pest spread was rated as medium. None of the pathways assessed was rated as low-risk. The study resulted in approximately one hundred recommendations for improved safeguarding in the GCR. The complete report can be accessed online at: http://caribbean-doc.ncsu.edu/index.htm.

The collimation system is a vital part of the LHC project, protecting the accelerator against unavoidable regular and irregular beam loss. About 80 collimators will be installed in the machine before the first run. Two insertion regions are dedicated to collimation and these regions will be among the most radioactive in the LHC. The space available in the collimation regions is very restricted, it was therefore important to ensure that the 3-D integration of these areas of the LHC tunnel would allow straightforward installation of collimators and also exchange of collimators under the remote handling constraints imposed by high radiation levels. The paper describes the 3-D integration studies and verifications of the collimation regions combining the restricted space available, the dimensions of the different types of collimators and the space needed for transport and handling. The paper explains how installation has been planned and carried out taking into account the handling.

For cost, planning and organisational reasons, it is often decided to install large pre-built accelerators components and physics detectors. As a result surface exceptional transports are required from the construction to the installation sites. Such heavy transports have been numerous during the LHC installation phase. This paper will describe the different types of transport techniques used to fit the particularities of accelerators and detectors components (weight, height, acceleration, planarity) as well as the measurement techniques for monitoring and the logistical aspects (organisation with the police, obstacles on the roads, etc). As far as oversized equipment is concerned, the lowering into the pit is challenging, as well as the transport in tunnel galleries in a very scare space and without handling means attached to the structure like overhead travelling cranes. From the PS accelerator to the LHC, handling systems have been developed at CERN to fit with these particular working conditions. This paper will expose the operating conditions of the main transport equipments used at CERN in PS, SPS and LHC tunnels.