Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Towards a Muon Collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work.Comment: 118 pages, 103 figure

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Erratum:Towards a muon collider

LPT

Erratum: Towards a muon collider

The original online version of this article was revised: The additional reference [139] has been added. Tao Han’s ORICD ID has been incorrectly assigned to Chengcheng Han and Chengcheng Han’s ORCID ID to Tao Han. Yang Ma’s ORCID ID has been incorrectly assigned to Lianliang Ma, and Lianliang Ma’s ORCID ID to Yang Ma. The original article has been corrected

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

Metrological characterisation of rotating-coil magnetometer systems

Rotating-coil magnetometers are among the most common and most accurate transducers for measuring the integral magnetic-field harmonics in accelerator magnets. The measurement uncertainty depends on the mechanical properties of the shafts, bearings, drive systems, and supports. Therefore, rotating coils require a careful analysis of the mechanical phenomena (static and dynamic) affecting the measurements, both in the design and in operation phases. The design phase involves the estimation of worst-case scenarios in terms of mechanical disturbances, while the operation phase reveals the actual mechanical characteristics of the system. In previous publications, we focused on modelling the rotating-coil mechanics for the design of novel devices. In this paper, we characterise a complete system in operation. First, the mechanical model is employed for estimating the forces arising during shaft rotation. Then, the effect of the estimated disturbances is evaluated in a simulated measurement. This measurement is then performed in the laboratory and the two results are compared. In order to characterise the robustness of the system against mechanical vibrations, different revolution speeds are evaluated. This work thus presents a complete procedure for characterising a rotating-coil magnetometer system

A magneto-mechanical model for rotating-coil magnetometers

Rotating-coil magnetometers are among the most common transducers for measuring local and integral magnetic fields of accelerator magnets. The measurement uncertainty strongly depends on the mechanical properties of the shafts, bearings, drive systems, and supports. This paper proposes an analytical mechanical model for rotating-coil magnetometers, which allows a sensitivity analysis of mechanical phenomena affecting magnetic measurements. Both static and dynamic effects are considered. The model is validated numerically with a finite element model, and experimentally on an operational device

Data-driven modeling of nonlinear materials in normal-conducting magnets

Accurate numerical modeling of normal-conducting accelerator magnets requires a reliable characterization of the iron saturation and hysteresis as well as a precise knowledge of the magnet geometry as built. Computations of the field quality are not easily achieving the accuracy required by the accelerator operation, particularly for eddy-current effects in fast-ramping magnets. This paper proposes a (measurement) data-driven model for the nonlinear magnetization of normal-conducting magnets. The model adopts a volume integral formulation compatible with eddy-current simulations. A two-step updating procedure is applied. The first step is the fitting of material parameters directly in the magnet model. The second step is the updating of the magnetization by measurements of the integral field harmonics. The result is a full-order updated model that can be employed in static or dynamic simulations. Finally, the procedure is validated on an iron-dominated, normal-conducting magnet

Data-driven simulation of transient fields in air–coil magnets for accelerators

Time-varying fields in fast-ramping magnets for accelerators are difficult to compute in the range of accuracy required for magnet operation. This is due to the complexity of the dynamic phenomena such as hysteresis and 3D eddy currents. On the other hand, magnetic measurements that intercept all these physical phenomena are often limited to a subset of excitation cycles and restricted spatial domains. The measurement results are therefore difficult to extrapolate without a validated physical model of the device. This paper proposes measurement-updated field simulations to characterize dynamic effects in accelerator magnets. The main idea is to construct a reduced-order model, whose variables are retrievable from measurements by means of a state estimator, and to update the model by minimizing the error between simulations and measurements. The proposed method is applied to a linear, time-transient electromagnetic-field problem of an air–coil corrector magnet with aluminium collars. The proposed method is a first step towards a hybrid twin of an accelerator magnet