The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) at CERN will include eight cryo-assemblies that are expected to be fabricated and delivered to CERN by the US HL-LHC Accelerator ...Upgrade Project (AUP) as part of the U.S. contributions to the HL-LHC. These cryostat assemblies are the quadrupole magnetic components of the HL-LHC Q1 and Q3 inner triplet optical elements in front of the two interaction points. Each cryo-assembly consists of two 4.2 m long Nb 3 Sn quadrupole magnets with aperture 150 mm and operating gradient 132.6 T/m. The first pre-series cryo-assembly has been fabricated and successfully tested at the horizontal test facility at Fermi National Accelerator Laboratory. In this manuscript we report the quench test results of the LQXFA/B-01 cryo-assembly. The primary objective of the horizontal test is full cryo-assembly qualification and validation of the performance requirements.
New high field and large-aperture quadrupole magnets for the low-beta inner triplets (Q1, Q2, Q3) have been built and tested as part of the high-luminosity upgrade of the Large Hadron Collider ...(HL-LHC). These new quadrupole magnets are based on Nb3Sn superconducting technology. The US Accelerator Upgrade Project (US-AUP) is producing the Q1 and Q3 Cryo-Assemblies: a pair of ∼5 m long magnet structures installed in a stainless-steel helium vessel (Cold Mass) and surrounded by cryostat shields, piping, and a vacuum vessel. This paper gives an overview of the design, production, and the results of the horizontal test of the first pre-series Q1/Q3 Cryo-Assembly.
Abstract
The United States has a rich history in high energy particle
accelerators and colliders — both lepton and hadron machines,
which have enabled several major discoveries in elementary particle
...physics. To ensure continued progress in the field, U.S. leadership
as a key partner in building next generation collider facilities
abroad is essential; also critically important is to prepare to host
an energy frontier collider in the U.S. once the construction of
the LBNF/DUNE project is completed. In this paper, we briefly
discuss the ongoing and potential U.S. engagement in proposed
collider projects abroad and present a number of future collider
options we have studied for hosting an energy frontier collider in
the U.S. We also call for initiating an integrated national R&D
program in the U.S. now, focused on future colliders.
Fermilab and CERN have started the development of 11 T Nb 3 Sn dipoles to replace a number of Large Hadron Collider (LHC) NbTi dipole magnets and free space for the additional collimators anticipated ...for the LHC luminosity upgrades. An essential step in the design of these magnets is the development of the 40-strand, high aspect ratio cable needed to achieve the nominal field of 11 T at the LHC operating current of 11.85 kA. To investigate conductors suited for this and other high-field magnet applications, a larger Superconducting Strand and Cable R&D lab was established at FNAL's Technical Division. Keystoned cables with and without a stainless steel core were developed and produced using 0.7 mm Nb 3 Sn strands made by Oxford Superconducting Technology with 127 (baseline) and 169 (advanced) restacks using the Restacked-Rod-Process. The electrical performance of these two strands is compared in cables made with different processes and geometries. Some of the effects of a cross-over in the cable were measured. Finally, it is shown how finite element modeling can be used as an aid in Rutherford-type cable design.
The upgrade of the LHC collimation system includes additional collimators in the LHC lattice. The longitudinal space for the collimators can be obtained by replacing some LHC main dipoles with ...shorter but stronger dipoles compatible with the LHC lattice and the existing powering circuits, cryogenics, and beam vacuum. A joint development programme aiming at building a 5.5 m long two-in-one aperture Nb 3 Sn dipole prototype suitable for installation in the LHC is being conducted by FNAL and CERN. As part of the first phase of the programme, 1 m and 2 m long single aperture models are being built and tested. Later on, the collared coils from these models will be assembled and tested in a two-in-one aperture configuration in both laboratories. A 2 m long practice model made of a single coil wound with Nb 3 Sn cable, MBHSM101, was developed and constructed at CERN. It has been completed, and tested at both 4.3 K and 1.9 K. This practice model features collared coils based on removable pole concept, S2-glass cable insulation braided over a mica layer, and coil end spacers made of sintered stainless steel with springy legs. The paper describes the main features of this practice model, the main manufacturing steps and the results of the cold tests.
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