168 research outputs found
Construction of the CERN Fast Cycled Superconducting Dipole Magnet Prototype
No full textCERN is pursuing a small scale R&D on a fast cycled superconducting dipole magnet (FCM) of interest for the upgrade plan of the LHC accelerator complex. The FCM dipole prototype being built has a number of novel features if compared to other magnets for similar applications. In this paper we describe the magnet design, and its expected performance, focusing especially on the novel features (magnetic circuit, mechanical supports, cooling) and on the details of the manufacturing procedure (coil winding and impregnation, joints, instrumentation and quench protection)
Design and fabrication of a single-aperture 11 T Nb 3Sn dipole model for LHC upgrades
No full textThe planned upgrade of the LHC collimation system includes additional collimators to be installed in the dispersion suppressor areas of points 2, 3 and 7. To provide the necessary longitudinal space for the collimators, a replacement of 8.33 T Nb-Ti LHC main dipoles with 11 T dipoles based on Nb 3Sn superconductor compatible with the LHC lattice and main systems is being considered. To demonstrate this possibility FNAL and CERN have started a joint program to develop a 2 m long single-aperture dipole magnet with the nominal field of 11 T at ∼11.85 kA current and 60 mm bore. This paper describes the demonstrator magnet magnetic and mechanical designs and analysis, coil fabrication procedure. The Nb 3Sn strand and cable parameters and test results are also reported
Design of 11 T Twin-Aperture NbSn Dipole Demonstrator Magnet for LHC Upgrades
No full textThe LHC collimation upgrade foresees two additional collimators installed in the dispersion suppressor regions of points 2, 3 and 7. To obtain the necessary longitudinal space for the collimators, a solution based on an 11 T dipole as replacement of the 8.33 T LHC main dipoles is being considered. CERN and FNAL have started a joint development program to demonstrate the feasibility of NbSn technology for this purpose. The program started with the development and test of a 2-m-long single-aperture demonstrator magnet. The goal of the second phase is the design and construction of a series of 2-m-long twin-aperture demonstrator magnets with a nominal field of 11 T at 11.85 kA current. This paper describes the electromagnetic design and gives a forecast of the field quality including saturation of the iron yoke and persistent-current effects in the NbSn coils. The mechanical design concepts based on separate collared coils, assembled in a vertically split iron yoke are also discussed
Quench Performance of a 1 m Long Single-Aperture 11 T NbSn Dipole Model for LHC Upgrades
No full textFNAL and CERN are performing a joint R&D program with the goal to build a 5.5-m long twin-aperture 11 T NbSn dipole prototype suitable for installation in the LHC. An important part of the program is the development and test of a series of short single-aperture and twin-aperture models with a nominal field of 11 T at the LHC nominal current of 11.85 kA and 20% margin. This paper describes design features and test results of a 1 m long single-aperture NbSn dipole model fabricated and tested at FNAL
Future Circular Collider Feasibility Study Report. Volume 3: Civil Engineering, Implementation and Sustainability
No full textVolume 3 of the FCC Feasibility Report presents studies related to civil engineering, the development of a project implementation scenario, and environmental and sustainability aspects. The report details the iterative improvements made to the civil engineering concepts since 2018, taking into account subsurface conditions, accelerator and experiment requirements, and territorial considerations. It outlines a technically feasible and economically viable civil engineering configuration that serves as the baseline for detailed subsurface investigations, construction design, cost estimation, and project implementation planning. Additionally, the report highlights ongoing subsurface investigations in key areas to support the development of an improved 3D subsurface model of the region. The report describes the development of the project scenario based on the “avoid-reduce-compensate” iterative optimization approach. The reference scenario balances optimal physics performance with territorial compatibility, implementation risks, and costs. Environmental field investigations covering almost 600 hectares of terrain—including numerous urban, economic, social, and technical aspects—confirmed the project's technical feasibility and contributed to the preparation of essential input documents for the formal project authorization phase. The summary also highlights the initiation of public dialogue as part of the authorization process. The results of a comprehensive socio-economic impact assessment, which included significant environmental effects, are presented. Even under the most conservative and stringent conditions, a positive benefit-cost ratio for the FCC-ee is obtained. Finally, the report provides a concise summary of the studies conducted to document the current state of the environment
The Pairing Matrix in Discrete Electromagnetism On the Geometry of Discrete de Rham Currents
No full textWe introduce pairing matrices on simplicial cell complexes in discrete electromagnetism as a means to avoid the explicit construction of a topologically dual complex. Interestingly, the Finite Element Method with first-order Whitney elements â when it is looked upon from a cell-method perspective â features pairing matrices and thus an implicitly defined dual mesh. We show that the pairing matrix can be used to construct discrete energy products. In this exercise we find that different formalisms lead to equivalent matrix representations. Discrete de Rham currents are an elegant way to subsume these geometrically equivalent but formally distinct ways of defining energy-products
BLM Threshold Strategy (UFOs and Quenches)
No full textThe interaction of the LHC’s proton beam with falling macroparticles (dust) in the beam tube causes beam losses with durations ranging from tens of microseconds to several milliseconds. After the long shutdown, the beam energy will be increased from 4 towards 6.5 TeV, as a consequence of which some of these beam-particle interactions, colloquially called “UFOs”, are predicted to cause quenches in superconducting magnets. In-depth experimental and numerical studies have been performed to make the most efficient use possible of the LHCs beam-loss monitoring (BLM) system to minimize the number of quenches, while keeping the number of avoidable beam dumps due to the BLM system to a minimum. The results of these studies are presented here, as well as preliminary strategies for the setting of BLM thresholds for the protection of warm magnets and collimators
Development and test of a single-aperture 11 T Nb3Sn demonstrator dipole for LHC upgrades
No full textThe upgrade of the LHC collimation system foresees installation of additional collimators around the LHC ring. The longitudinal space for the collimators could be provided by replacing some 8.33 T NbTi LHC main dipoles with shorter 11 T Nb3Sn dipoles compatible with the LHC lattice and main systems. To demonstrate this possibility, FNAL and CERN have started a joint program with the goal of building a 5.5 m long twin-aperture dipole prototype suitable for installation in the LHC. The first step of this program is the development of a 2 m long single-aperture demonstrator dipole with a nominal field of 11 T at the LHC nominal current of 11.85 kA and ∼20% margin. This paper describes the design, construction, and test results of the first single-aperture Nb3Sn demonstrator dipole model
The pairing matrix in discrete electromagnetism
No full textWe introduce pairing matrices on simplicial cell complexes in discrete electromagnetism as a means to avoid the explicit construction of a topologically dual complex. Interestingly, the Finite Element Method with first-order Whitney elements — when it is looked upon from a cell-method perspective — features pairing matrices and thus an implicitly defined dual mesh. We show that the pairing matrix can be used to construct discrete energy products. In this exercise we find that different formalisms lead to equivalent matrix representations. Discrete de Rham currents are an elegant way to subsume these geometrically equivalent but formally distinct ways of defining energy-products
Quench Protection Study of a Single-Aperture 11 T Nb3Sn Demonstrator Dipole for LHC Upgrades
No full textThe planned upgrade of the Large Hadron Collider (LHC) collimation system will include installation of additional collimators in the dispersion suppressor areas. The longitudinal space for the collimators could be provided by replacing 15-m-long 8.33 T NbTi LHC main dipoles with shorter 11 T Nb 3Sn dipoles compatible with the LHC lattice and main systems. FNAL and CERN have started a joint program with the goal of building a 5.5-m-long twin-aperture Nb3Sn dipole prototype suitable for installation in the LHC. The first step of this program is the development of a 2-m-long single-aperture demonstrator dipole with a nominal field of 11 T at the LHC nominal current of 11.85 kA. This paper summarizes the results of quench protection studies of 11 T dipoles performed using the single-aperture Nb 3Sn demonstrator
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