The LHC Insertion Magnets

The Large Hadron Collider comprises eight insertions, four of which are dedicated to the LHC experiments while the others are used for the major collider systems. The various functions of the insertions are fulfilled by a variety of magnet systems, most of them based on the technology of NbTi superconductors cooled by superfluid helium at 1.9 K. A number of stand-alone magnets in the matching sections are operated at 4.5 K, while in the high radiation areas specialised resistive magnets are used. In this paper, we review the concepts underlying the design of the LHC insertions, and report on the design, procurement and testing of the various specialised magnet systems

Status and Challenges of the LHC Construction

The LHC is designed to provide proton beams of 7 TeV and nominal luminosity of 10**34 cm**-2s**-1. This objective is achieved at an affordable cost by pushing all major collider components to the limits of technology, by upgrading the existing CERN accelerators and infrastructure, and by involving the technical expertise, resources and dedication of accelerator laboratories world-wide. Following a decade of intensive R&D and technical validation of major collider systems, the LHC construction is now fully underway. Major industrial contracts have been awarded and are in execution for the procurement of the magnet, cryogenics and other systems. In this report, the status of the design and construction of the major LHC systems is presented

Phased approach to the LHC Insertion Upgrade and Magnet Challenges

The LHC is on its way for operation with beam in 2008. The first goal of CERN and the LHC community is to ensure that the collider is operated efficiently, gradually reaching its maximal performance. In parallel, discussions have started and there is already a wealth of ideas on the possible directions for upgrading the LHC insertions. In this talk, we illustrate some of the constraints limiting the upgrade scenarios, and argue that a phased approach with several intermediate targets is necessary. In the first phase, the known bottleneck in the low-β triplets needs to be removed in the perspective of the physics run of 2013. This phase relies on the mature Nb-Ti superconducting magnet technology, where improvements for a small scale production are still possible

LHC Interaction Region Upgrade: Phase I

The LHC is starting operation with beam in 2008. The primary goal of CERN and the LHC community is to ensure that the collider is operated efficiently, maximizing its physics reach, and to achieve the nominal performance in the shortest term. Since several years the community has been discussing the directions for upgrading the experiments, in particular ATLAS and CMS, the LHC machine and the CERN proton injector complex. A well substantiated and coherent scenario for the first phase of the upgrade, which is foreseen in 2013, is now approved by CERN Council. In this paper, we present the goals and the proposed conceptual solution for the Phase-I upgrade of the LHC interaction regions. This phase relies on the mature Nb-Ti superconducting magnet technology, with the target of increasing the luminosity by a factor of 2-3 with respect to the nominal luminosity of 1034 cm-2s-1, while maximising the use of the existing infrastructure

LHC instertion upgrade combining $Nb_{3}Sn and Nb-Ti magnets

Superconducting magnet technology based on Nb-Ti cable cooled at 1.9 K has provided the present generation of LHC magnets. Magnetic fields above 10 T that will be required in future accelerators, including the upgrade of the LHC, call for the use of brittle conductors, such as Nb$_{3}$Sn or Nb3Al. However, these conductors are proving difficult to use, and while the development of acceleratortype magnets (dipoles and quadrupoles) is advancing, it is likely to be some time before we will be confident enough to replace sections of the LHC (for example the magnets of the inner triplets) using the new technology. It is shown that Nb-Ti superconducting magnets operating at 1.9 K could provide a viable intermediate step for the upgrade of the LHC insertions, taking advantage of the established technology, and including improvements that could be reasonably applied to a small-scale magnet production. Moreover, by incorporating one (or two) relatively short Nb$_{3}$Sn quadrupoles in each triplet, the optical and heat load performance could be tailored to approach that of triplets made entirely from Nb$_{3}$Sn magnets and allow us to consider an early upgrade with larger aperture magnets but having only limited reliance on Nb$_{3}$Sn technology

Production performance of hydraulic fractures in tight gas sands, a numerical simulation approach. Journal of Petroleum Science and Engineering

Hydraulically fractured tight gas reservoirs are one of the most common unconventional gas sources being produced today, and will be a regular source of gas in the future. The extremely low permeability of tight gas sands leads to inaccuracy of conventional build-up and draw-down well test results. This is primarily due to the increased time required for transient flow in tight gas sands to reach pseudo-steady state condition. To increase accuracy, well tests for tight gas reservoirs must be run for longer periods of time which is in most cases not economically viable. The large amount of downtime required to conduct well tests in tight sands makes them far less economical than conventional reservoirs, which leads to the need for accurate simulation of tight gas reservoir well tests. This paper presents simulation results of a 3-D hydraulically fractured tight gas model created using Eclipse software. The key aims are to analyze the effect of differing fracture orientation, number and length. The focus of the simulation runs will be on the effect of hydraulic fracture orientation and length. The results will be compared to simulation runs without the abovementioned factors to determine their effects on production rates and well performance analysis. All results are plotted alongside an un-fractured tight gas scenario in order to put the hydraulic fracture performance in perspective. Key findings from this work include an approximately linear relationship between initial gas rate and the number of hydraulic fractures intersecting the wellbore. In addition, fracture length is found to have less of an impact on initial gas rate compared to number of fractures intersecting the wellbore, for comparable total fracture volumes

Low Gradient, Large Aperture IR Upgrade Options for the LHC compatible with Nb-Ti Magnet Technology

The paper presents three different layout and optics solutions for the upgrade of LHC insertions using Nb-Ti superconducting quadrupoles. Each solution is the outcome of different driving design criteria: a) a compact triplet using low gradient quadrupoles; b) a triplet using low gradient quadrupoles of modular design, and c) a layout minimizing the B-max while using modular magnets. The paper discusses the different strategies and design criteria for the three solutions. It also discusses their relative advantages and disadvantages and identifies outstanding studies that need to be addressed in order to develop the solutions further. All cases assume that the first quadrupole magnet requires a smaller minimum aperture and therefore, can feature a slightly larger gradient than the remaining final focus quadrupole magnets