Andrea Bersani

DUNE (Deep Underground Neutrino Experiment) is a long-baseline neutrino oscillation experiment currently under construction, whose far detectors will be the largest liquid argon time projection chambers ever built. This detector design calls for custom-built cryogenic front-end electronics to meet its performance requirements. This paper describes the charge readout electronics that will be used in the DUNE horizontal drift (HD) far detector and presents performance results using data from the ProtoDUNE-HD detector, a 770 ton liquid argon time projection chamber operated at the CERN Neutrino Platform in 2024 that served as the final prototype of the DUNE HD design.

Among the most innovative and promising next generation particle accelerators, a muon collider is at a time a viable compromise between the increase of available energy at the interaction point and the sustainability of the related infrastructure. The International Muon Collider Collaboration is pursuing the design of a complete accelerator complex, up to the detectors to be installed on the two interaction points foreseen on the collider. Here we present a preliminary design of a solenoid magnet for one of the proposed detectors, MUSIC, aiming at a compromise between the requests for the detector tracker and the beam-induced background rejection. The goal is to achieve up to 5 T at the interaction point, good field uniformity (of the order of 10%) on a volume comparable with the warm bore of the solenoid (4.6 metres in diameter and 4.6 metres long), non trivial integration with the sub detectors and with the final focusing magnets of the collider, which are foreseen at less than 8 metres from the magnet centre. Starting from a CMS-like design, we plan to fulfil the requirements with a central solenoid coupled with additional coils embedded in the hadronic calorimeter and the end caps of the return yoke.

We present the measurement of π + -argon inelastic cross sections using the ProtoDUNE single-phase liquid argon time projection chamber in the incident π + kinetic energy range of 500–800 MeV in multiple exclusive channels (absorption, charge exchange, and the remaining inelastic interactions). The results of this analysis are important inputs to simulations of liquid argon neutrino experiments such as the Deep Underground Neutrino Experiment and the Short Baseline Neutrino program at Fermi National Accelerator Laboratory. They will be employed to improve the modeling of final state interactions within neutrino event generators used by these experiments, as well as the modeling of π + -argon secondary interactions within the liquid argon. This is the first measurement of π + -argon absorption at this kinetic energy range as well as the first ever measurement of π + -argon charge exchange.

Simulation of quench dynamics in superconducting magnets is essential for understanding their thermal and electromagnetic behavior during fault conditions. Numerically, this represents a complex multi-physics problem encompassing thermal, electrical, and magnetic phenomena. This contribution introduces an advanced application developed using the ANSYS APDL program to simulate the quench behavior of superconducting magnets. The tool supports various geometries, including cos-theta, canted cos-theta, and solenoid configurations, making it highly versatile for diverse applications. Furthermore, the use of ANSYS APDL commercial software allows for the easy import of field information and cable configuration information directly from electromagnetic simulations. While ANSYS commonly models temperature-dependent material properties, our simulation framework extends this capability to include magnetic field-dependent material properties in the cable, such as magneto-resistivity and the superconducting critical temperature during transient states. An extensive thermal model was produced to simulate the development of Joule heating in superconducting cables, heat propagation across adjacent cables, helium cooling, and the effect of quench-heaters (QHs). Since simulating the behavior of an entire magnet in an electro-thermal transient is a particularly demanding application in terms of computation times, particular attention has been paid to developing strategies to accurately simulate magnet quench with the least possible load on the machine. We compare the performance of our tool with the already available quench simulation software and data from the quench tests of the MBRD magnet prototype for the LHC-HL upgrade.

Following the publication of [1], the authors identified an error in the author list. Diego Perini has therefore been removed from the author list with agreement of all authors.

Over the past few years, interest in a Muon Collider as a potential post-LHC machine has grown significantly. By colliding muons, it is possible to achieve both precision and high energy, overcoming the limitations of synchrotron radiation in conventional lepton colliders. However, the very short muon lifetime at rest requires high beam intensity and fast acceleration rates limiting the collider ring dimensions. These limitations lead to several challenges in the design of superconducting magnets, which must generate high magnetic fields in large apertures to provide shielding from the radiation due to muon decay. This work explores the design of combined function magnets, which are essential to address the neutrino flux issue in straight sections by bending the particles during focusing/defocusing stages. The superconducting material selected for these magnets is REBCO, a High Temperature Superconductor (HTS), with operating temperatures ranging from 4.5 K to 20 K. Various configurations of combined function magnets are studied and simulated using a Python code interfaced with the Finite Element Method (FEM) software ANSYS, employing the sector coil approximation. The goal is to identify feasible designs that can accommodate substantial internal shielding while continuing to provide the high fields and gradients demanded by the lattice optics. To validate the manufacturability of such concepts, a preliminary winding test has been performed using Nb$_{3}$Sn in a Canted-Cosine-Theta (CCT) geometry. While REBCO represents the most promising HTS conductor for future high-field applications, Nb$_{3}$Sn remains one of the most mature options for large accelerator magnets, providing a valuable feasibility benchmark.

During the Long Shutdown 3 of the LHC, scheduled to start in 2026, the interaction regions will be upgraded to increase the integrated luminosity by about one order of magnitude. Among the components to be replaced are the MBRD (Main Bending Recombination Dipole, also known as D2), which are double-aperture magnets providing aligned magnetic fields to steer the two beams into the ATLAS and CMS experiments and subsequently recombine them onto their nominal trajectories. To meet the demanding requirements of the High-Luminosity LHC, a new magnet design was developed by INFN-Genova, featuring a larger aperture, a higher operating field, and innovative solutions to mitigate the strong electromagnetic cross-talk between the apertures while ensuring mechanical integrity against the large repulsive Lorentz forces. The development program included the construction of a 1.6-m model, a full-length prototype, and six series magnets, of which four will be installed in the LHC and two kept as spares. Series production is ongoing at ASG Superconductors, and the first magnet has been successfully cold-tested at CERN. This contribution reports on the main challenges faced during series production and discusses the first test results.

An International Muon Collider Collaboration (IMCC) has been formed following the recommendation of the Updated European Strategy for Particle Physics (ESPPU) to study the feasibility of a 10 TeV muon collider within a compact 10 km ring. This machine combines the precision of lepton colliders with the energy reach and discovery potential of hadron colliders, overcoming synchrotron radiation limitations affecting electron-positron machines. However, the short muon lifetime (2.2 μs at rest) presents several challenges in the development of magnets, RF systems, targets, shielding, and cooling. Super conducting magnets of the collider ring are influenced by the need for tungsten shields inside the bore apertures to protect superconducting coils from radiation caused by muon decay, as well as the elimination of straight sections in the accelerator to mitigate harmful neutrino-induced radiation. This work extends the Aperture-Field (A–B) plot methodology, previously applied to dipoles and quadrupoles, to sextupole magnets, delineating feasible designs based on aperture, sextupolar gradient strength, mechanical stress, quench protection, and cost. Using a Python ANSYS tool, optimized configurations were simulated under the sector coil approximation, focusing on REBCO coils operating at 4.5 K, 10 K, and 20 K, providing Aperture– Sextupole Gradient (A–G2) plots for the sextupoles standalone and Dipole Field Sextupole Gradient (B–G2) plots for the sextupoles combined with dipoles. These results provide a quantitative framework to evaluate the achievable field strengths and geometric constraints of sextupole-based solutions in the demanding environment of a high-energy muon collider.

The FalconD project (Future Accelerator post-LHC Optimized Nb$_{3}$Sn Dipole), conducted by INFN Genoa and Milan in collaboration with CERN, is dedicated to the development of a 1.5 m long, 12 T Nb$_{3}$Sn dipole. Nb$_{3}$Sn has already proven its effectiveness in accelerator magnets, and its application to bending dipoles is a key step toward future high-field accelerator technologies. A major challenge of the design is the mechanical structure, which must withstand the substantial Lorentz forces generated by the high magnetic field. To address this, the innovative bladder and key (B $\text{&}$ K) concept is adopted, applied here for the first time to a cos-theta dipole. This contribution presents a 2D finite element mechanical analysis of the FalconD, focusing on stress distribution and gap evolution during the main assembly and operational stages, with the aim of validating the design approach.