Mechanical Design of the MARCO Solenoid Detector Magnet

Journal Article · Mon Oct 06 00:00:00 EDT 2025 · IEEE Transactions on Applied Superconductivity

DOI:https://doi.org/10.1109/TASC.2025.3618167· OSTI ID:2997740

Reymond, Hugo ^[1]; Berriaud, C. ^[1]; Calvelli, V. ^[1]; Ghoshal, P. ^[2]; Gopinath, S. ^[2]; Juster, F.-P. ^[1]; Lottin, J.-P. ^[1]; Quettier, L. ^[1]; Segreti, M. ^[1]; Simon, D. ^[1]; Stacchi, F. ^[1]; Sun, E. ^[2]; Young, D. ^[2]; Rajput-Ghoshal, R. ^[2]

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1. Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France). Institut de Recherche sur les Lois Fondamentales de l'Univers (IRFU)
2. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

MARCO is the superconducting solenoid for ePIC, the new particle physics detector of the upcoming Electron Ion Collider (EIC) at the Brookhaven National Laboratory (NY, USA). The magnet has a 2.84 m warm bore diameter and is 3.85 m long. This 15 tons magnet provides a 2.0 T central field at the interaction point with a nominal current of about 4 kA at 4.5 K. The coil is composed of 6 layers of copper stabilized NbTi Rutherford in channel conductor (RIC) and it is wound internally to the brass mandrel. Here, this paper presents the detailed mechanical design of the magnet, starting with the magnet description, the material properties and the acceptance criteria considered. Then, the coil pack properties homogenization process is described. Subsequently, the 2D and 3D calculation models and their assumptions are described. At last, the computational results for the cool down and the energization are discussed. Index Terms—Superconducting Detector Magnet, material properties, homogenization, detector, EIC.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: AC05-06OR23177
• OSTI ID: 2997740
• Report Number(s): DOE/OR/23177--7833; JLAB-PHY--25-4274
• Journal Information: IEEE Transactions on Applied Superconductivity, Journal Name: IEEE Transactions on Applied Superconductivity; ISSN 1051-8223; ISSN 2378-7074; ISSN 1558-2515
• Publisher: Institute of Electrical and Electronics Engineers (IEEE)
• Country of Publication: United States
• Language: English