ESSnuSB is a design study for an experiment to measure the CP violation in the leptonic sector at the second neutrino oscillation maximum using a neutrino beam driven by the uniquely powerful ESS linear accelerator. The reduced impact of systematic errors on sensitivity at the second maximum allows for a very precise measurement of the CP violating parameter. This review describes the fundamental advantages of measurement at the second maximum, the necessary upgrades to the ESS linac in order to produce a neutrino beam, the near and far detector complexes, and the expected physics reach of the proposed ESSnuSB experiment, concluding with the near future developments aimed at the project realization.
1 February 2023 in IEEE Transactions on Applied Superconductivity
A prototype CCT dipole magnet developed by a collaboration between Swedish universities, Swedish industry and CERN will be tested at Uppsala University. This 1 m long double-aperture magnet can provide a field strength of 3.3 T at 85 A in a 70 mm aperture with an integrated field of 2.8 Tm. It is intended to replace the current LHC orbit corrector magnets which are reaching the end of their expected life due to the radiation load. The new magnet is designed to handle the radiation dose of the upgrade to the high-luminosity LHC, which will deliver about ten times the current radiation dose. It must therefore be more resistant to radiation and meet strict requirements in terms of electrical insulation while matching the original field quality and self-protective capability, mechanical volume, and maximum excitation current. This paper will present the latest of the design and manufacturing work, including the results of simulations of the mechanical field and the mechanical stress. Details of the various tests performed before machining the parts are also presented.
1 August 2012 in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
In the framework of the future circular collider study, a new septum magnet concept (“SuShi”) has been developed, and a prototype was built at Wigner RCP, and tested at the FREIA facility of Uppsala University. The concept uses a canted cosine theta (CCT)-like superconducting magnet and a passive superconducting shield to create a zero-field and high-field region within its aperture. SuShi is the first CCT magnet with both of its winding layers simultaneously impregnated with wax. Details of the construction will be presented, with special emphasis on the wax impregnation procedure which deals with the $\sim$ 15% contraction of wax upon solidification. The empty magnet (no shield in its aperture) was powered without training to 450 A with a peak field of 3.64 T, corresponding to 80% of the short sample limit of the conductor along the load line. No quench or other anomaly was observed during the entire testing period. A clear onset of quench-back was observed above about 200 A.
1 March 2024 in Superconductor Science and Technology
In the framework of the Future Circular Collider Study a new septum magnet concept, nicknamed ‘SuShi’ has been developed, and a prototype was built at Wigner Research Center for Physics, and tested at the FREIA facility of Uppsala University in April 2023. The concept uses a canted cosine theta (CCT)-like superconducting magnet and a passive superconducting shield to create a zero-field and high-field region within its aperture. SuShi is the first CCT magnet with both of its winding layers simultaneously impregnated with wax. This paper describes the first powering test of the empty magnet at 4.2 K, without the shield being inserted in its aperture. The performance of the magnet, including the observation of quench-back, estimation of hot-spot temperatures and the fraction of energy dissipated in the magnet are presented, and most interestingly the absence of any quench during the entire testing period is reported. Sushi reached its nominal +5% peak field of 3.64 T at 450 A, which corresponds to 80% of the calculated short sample limit along the load line, without training.
24 February 2022 in IEEE Transactions on Applied Superconductivity
The High Luminosity LHC requires dipole orbit correctors grouped in double aperture magnet assemblies. They provide a field of 3.1 T at 100 A in an aperture of 70 mm. The current standard design is a classical cosine-theta layout made with ribbon cable. However, the electric insulation of this cable is not radiation-resistant enough to withstand the radiation load expected in the coming years of LHC operation. A new design, based on a cable with polyimide insulator, that can replace the existing orbit correctors, is needed. The challenge is to design a magnet that fits directly into the existing positions and that can operate with the same busbars, passive quench protection, and power supplies. The new orbit corrector design meets high requirements on the field quality while keeping within the same mechanical volume and maximum excitation current. A collaboration of Swedish universities and Swedish industry has been formed for the development and production of a prototype magnet following a concurrent engineering methodology to reduce the time needed to produce a CCT magnet. The magnet has a 1 m long CCT dipole layout consisting of two coils. The superconductor is a commercially available 0.33 mm wire with polyimide insulation in a 6-around-1 cable. The channels in the coil formers, that determine the CCT layout, allow for $2\times 5$ cable layers. A total of 70 windings makes that the coil current can be kept below 100 A. We will present the detailed design and preliminary quench simulations.