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Sabbi, GianLuca

Publications and source records attributed to Sabbi, GianLuca.

High-Field Magnets for Future Hadron Colliders

Recent strategy updates by the international particle physics community have confirmed strong interest in a next-generation energy frontier collider after completion of the High-Luminosity LHC program and construction of a e + e - Higgs factory. Both hadron and muon colliders provide a path toward the highest energies, and both require significant and sustained development to achieve technical readiness and optimize the design. For hadron colliders, the energy reach is determined by machine circumference and the strength of the guiding magnetic field. To achieve a collision energy of 100 TeV while limiting the circumference to 100 km, a dipole field of 16 T is required and is within the reach of niobium–tin magnets operating at 1.9 K. Magnets based on high-temperature superconductors may enable a range of alternatives, including a more compact footprint, a reduction of the cooling power, or a further increase of the collision energy to 150 TeV. The feasibility and cost of the magnet system will determine the possible options and optimal configurations. In this article, I review the historical milestones and recent progress in superconducting materials, design concepts, magnet fabrication, and test results and emphasize current developments that have the potential to address the most significant challenges and shape future directions.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Progress on the design of the interaction region of the Electron-Ion Collider EIC

We present an update on the design of the Interaction Region (IR) for the the Electron Ion Collider (EIC) being built at Brookhaven National Laboratory (BNL). The EIC will collide high energy and highly polarized hadron and electron beams with a center of mass energy up to 140 GeV with luminosities of up to 10^34 /cm^2/s. The IR, located at RHIC's IR6, is designed to meet the requirements of the nuclear physics community as outlined in [1]. A second IR is technically feasible but not part of the project.The magnet apertures are sufficiently large to allow desired collision products to reach the far-forward detectors; the electron magnet apertures in the rear direction are chosen to be large enough to pass the synchrotron radiation fan. In the forward direction the electron apertures are large enough for non-Gaussian tails.The paper discusses a number of recent recent changes to the design. The machine free region was recently increased from 9 to 9.5 m to allow for more space in the forward direction for the detector. The superconducting magnets on the forward side now operate at 1.9 K, which helps crosstalk and space issues.

43 PARTICLE ACCELERATORS↗

Challenges and Lessons Learned From Fabrication, Testing, and Analysis of Eight MQXFA Low Beta Quadrupole Magnets for HL-LHC

By the end of October 2022, the US HL-LHC Accelerator Upgrade Project (AUP) had completed fabrication of ten MQXFA magnets and tested eight of them. The MQXFA magnets are the low-beta quadrupole magnets to be used in the Q1 and Q3 Inner Triplet elements of the High Luminosity LHC. This AUP effort is shared by BNL, Fermilab, and LBNL, with strand verification tests at NHMFL. An important step of the AUP QA plan is the testing of MQXFA magnets in a vertical cryostat at BNL. The acceptance criteria that could be tested at BNL were all met by the first four production magnets (MQXFA03-MQXFA06). Subsequently, two magnets (MQXFA07 and MQXFA08) did not meet some of the criteria and were disassembled. Furthermore, lessons learned during the disassembly of MQXFA07 caused a revision to the assembly specifications that were used for MQXFA10 and subsequent magnets. In this article, we present a summary of 1) the fabrication and test data for all the MQXFA magnets; 2) the analysis of MQXFA07/A08 test results with characterization of the limiting mechanism; 3) the outcome of the investigation, including the lessons learned during MQXFA07 disassembly; and 4) the finite element analysis correlating observations with test performance.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

High-Field Design Concept for Second Interaction Region of the Electron-Ion Collider

Efficient realization of the scientific potential of the Electron Ion Collider (EIC) calls for addition of a future second Interaction Region (2nd IR) and a detector in the RHIC IR8 region after the EIC project completion. The second IR and detector are needed to independently cross-check the results of the first detector, and to provide measurements with complementary acceptance. The available space in the existing RHIC IR8 and maximum fields achievable with NbTi superconducting magnet technology impose constraints on the 2nd IR performance. Since commissioning of the 2nd IR is envisioned in a few years after the first IR, such a long time frame allows for more R&D on the Nb₃Sn magnet technology. Thus, it could provide a potential alternative technology choice for the 2nd IR magnets. Presently, we are exploring its potential benefits for the 2nd IR performance, such as improvement of the luminosity and acceptance, and are also assessing the technical risks associated with use of Nb₃Sn magnets. In this paper, we present the current progress of this work.

43 PARTICLE ACCELERATORS↗

Development and demonstration of next generation technology for Nb_3Sn accelerator magnets with lower cost, improved performance uniformity, and higher operating point in the 12-14 T range

The scope of the proposal outlined in this white paper is the development and demonstration of the technology needed for next generation of Nb_3Sn accelerator magnets in the 12-14 T range. The main goal is to cut magnet cold-mass cost by a factor 2 or higher with respect to the Nb_3Sn magnets produced by the US Accelerator Upgrade Project (AUP) for the High-Luminosity Large Hadron Collider (HL-LHC). This goal will be achieved by significant reduction of labor hours, higher operating point, and improved performance uniformity. A key factor will be automation that will be achieved through industry involvement and benefitting from the experience gained in US national laboratories through the production of the AUP magnets. This partnership will enable the development of a technology that will be easily transferable to industry for mid- and large-scale production of Nb_3Sn accelerator magnets in the 12-14 T range. This step is essential to enable next generation of colliders such as the FNAL-proposed Muon Collider, FCC and other HEP hadron colliders. This is a Directed R&D where direction is given by the field range and industry involvement for high-automation and industry-ready technology. The plan includes ten milestones, to be achieved in 6-8 years at the cost of 5-7 $M/year.

43 PARTICLE ACCELERATORS↗

Magnetic and Mechanical Analysis of a Large Aperture 15 T Cable Test Facility Dipole Magnet

The US Department of Energy (DOE) Office of Science (SC), is funding a large bore “Cable Test Facility Magnet” for testing advanced cables and inserts in high transverse field. This is a joint effort between the Office of High Energy Physics (HEP) and the Office of Fusion Energy Sciences (FES). The background field magnet for this facility is being developed at Lawrence Berkeley National Laboratory (LBNL) while the cryostat and test facility will be located and operated by Fermi National Accelerator Laboratory (FNAL). The Nb 3 Sn dipole magnet, which will provide the transverse background field, is designed to generate a field of 15 T in a 100 × 150 mm bore at 1.9 K. The conceptual design of a block-type dipole with flared ends and a structure based on key-and-bladder technology will be introduced. The results of the magnetic and mechanical analysis will be presented.

43 PARTICLE ACCELERATORS↗

3D Mechanical Analysis of a Compact Nb 3 Sn IR Quadrupole for EIC

Abstract-The Electron Ion Collider (EIC) will require large aperture quadrupole magnets for the Hadron beam in the insertion region. Key requirements include high field, compact size, and tight control of the fringe fields. A 120 mm aperture, 308.4 mm outer diameter actively shielded Nb 3 Sn quadrupole model is under development to support these goals. This work is being carried out by a collaboration of BNL, JLAB and LBNL. A compact shell-based structure preloaded with a bladder and key system was developed for this project. In this paper, the effect of the compact structure on the mechanical behavior was investigated. In particular, the impact of the assembly tolerances and coil size variations on the actual coil stresses and bladder pressures was computed and compared with results from larger bladder and key structures developed for the LHC IR. The longitudinal preload is provided by stainless steel rods. Differently from other bladder and key magnets, the rods are first preloaded axially before coil axial load is applied. This new design aims to increase the overall stiffness of the system and reduce the longitudinal coil displacement during powering. Based on the results of a 3D mechanical analysis, the preliminary preload targets for the EIC quadrupole assembly will be reviewed and discussed.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Lessons Learned From the Prototypes of the MQXFA Low-Beta Quadrupoles for HL-LHC and Status of Production in the US

With the successful test of the first two pre-series magnets the US HL-LHC Accelerator Upgrade Project has started production of the MQXFA magnets to be used in Q1/Q3 inner triplet elements of the HL-LHC. This good start comes after the test of two prototypes with limited performance, and it demonstrates the importance of learning from past issues. Therefore, in this paper we want to share the most important lessons learned so far, focusing on those which may be more interesting for similar projects. Additionally, we will present the status of MQXFA fabrication in the US.

43 PARTICLE ACCELERATORS↗

US HL-LHC Accelerator Upgrade Project, Acceptance Criteria Part A: MQXFA Magnet

This document specifies the functional requirements for the MQXFA magnet readapted for the American contribution. If all the requirements specified in this document are met, then the U.S. HL-LHC AUP MQXFA deliverables will be accepted by CERN for the HL-LHC project. Another separate document will be issued by the American contribution for the MQXFA cold mass functional requirements. Please note that the definition of threshold as it is being used by the American contribution is not the same as objective, according to the HL-LHC quality policy.

42 ENGINEERING↗