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Ukrainian contributions to particle physics: history and prospects Українськi внески у фізикy частинок: минуле та перспективи
No full textTraining Evaluation of Separation Dipoles in HL-LHC
No full textA series production of beam separation dipole, MBXF, is underway toward the High-Luminosity Large Hadron Collider upgrade (HL-LHC). So far, High Energy Accelerator Research Organization (KEK) have tested 4 series magnets in our own vertical cryostat, and their quench training performances have been successfully evaluated. The results show different training behaviors, and particularly MBXF3 has a slower training rate even after the thermal cycle (TC). Quench-antenna (QA) signals for such the magnet shows a prominent oscillatory pattern due to mechanical disturbance. In order to understand origin of the different training behaviors, a new data-acquisition system has been introduced to detect QA activities during powering the magnet. The system was first demonstrated in the second cooldown (CD) of MBXF5 (Apr. - May ’25), and the training evolution became clearly visible: Mechanical activities cease with each training cycle while appearance of the activities was confirmed after TC indicating loss of the training memory. We expect that this new detection tool can help to understand the reason of the different training rate, and thus it will be used for rest of the MBXF tests
Updates on the Conceptual Design Study of the Magnets for the Muon Collider Storage Ring
No full textThe Muon Collider represents an exciting proposal for a post-LHC accelerator, capable of exploring higher-energy
regions with greater power consumption efficiency compared to hadronic alternatives, while avoiding synchrotron radiation limitations inherent in electron colliders. This contribution will focus on the magnets for the Muon Collider storage ring. These magnets pose an unprecedented technological challenge: high magnetic fields are required to ensure the compactness of the ring, maximizing the number of muon beam passes through the interaction region and thereby increasing luminosity. Additionally, large apertures are essential to accommodate an adequate shielding system that keeps the thermal and nuclear loads induced by the beam within acceptable limits. Furthermore, minimizing straight sections is critical to avoid the radioactive hazard posed by collimated neutrino beams, necessitating the use of combined-function magnets (dipole + quadrupole and dipole + sextupole). The interaction region also presents extreme conditions that demand the development of magnets beyond the current state of the art. In this contribution, we will discuss the progress in the feasibility study of magnets for both the arc and the interaction region of the Muon Collider storage ring. Performance limits will be analyzed for dipoles and quadrupoles, taking into consideration constraints on mechanical stresses, margin on the load line, ease of the protection system and cost for ReBCO-based magnets. Finally, the most up-to-date conceptual designs of the arc dipole will be presented, comparing the strengths and challenges of the cos-theta and block coil layouts in terms of achieving of electromagnetic requirements, mechanical structure feasibility, and windability
Toward a Reduced Helium Content Cryogenic Cooling Scheme at 4.5 K for CERN’s FCC-hh Accelerator
No full textA conceptual design for cooling superconducting ac-
celerator magnets operating at 4.5 K is proposed for the hadron-
hadron configuration of the Future Circular Collider (FCC-hh).
This is motivated by efforts to reduce helium inventory and energy
costs, while ensuring compatibility with the tunnel structure envis-
aged for FCC-ee, and providing a technically viable solution for
the magnets. The study is carried out for the latest configuration of
the FCC-hh machine, the so-called F14 scenario, that uses Nb3Sn
superconducting magnets with an operational magnetic field of
14 T, for a centre-of-mass energy of 85 TeV with a magnetic
filling scheme of 83%. The updated heat loads are presented, along
with expected longitudinal and radial temperature gradients in the
magnet structure. The move from 1.9 K operation, which makes
extensive use of He II, towards 4.5 K using single-phase helium
significantly reduces the overall cryogenic power consumption by
30%, and the machine’s helium inventory by 50%
Magnet System of the New Electron Cooler for the CERN Antiproton Decelerator (AD) Ring
No full textA new electron cooler for the Antiproton Decelerator (AD) ring at CERN is under construction and will be installed in the next long shutdown (2026-2028) to replace the existing 40-year-old device. This paper presents the design of the new electron cooler’s normal conducting magnet system comprising three straight solenoid sections joined by two toroidal field sections. Compared to the existing electron cooler magnet system, the new magnet system gives a factor five improvement of cooling region field quality. The field correction scheme used to achieve this improvement will be discussed in detail. The upgrade has the potential to reduce the length of the electron cooling plateaus in the AD cycle and thereby increase the number of antiprotons available to CERN’s rich antimatter physics program