C. Berriaud

Bio: C. Berriaud is an academic researcher from CERN. The author has contributed to research in topics: Magnetic energy & Magnet. The author has an hindex of 1, co-authored 1 publications receiving 9 citations.

Evolution of the Conceptual FCC-hh Baseline Detector Magnet Design

Abstract: As a part of the future circular collider conceptual design study for hadron-hadron physics (FCC-hh), conceptual designs of detector magnets are being developed to facilitate the measurement of particle products resulting from the 100-TeV collisions. This paper discusses the design evolution leading from a 65-GJ twin solenoid with forward dipoles design to the present baseline design that features three superconducting solenoids. The central magnet produces 4 T over a free bore of 10 m and a length of 20 m. The forward solenoids provide additional bending power to facilitate tracking of high-pseudo-rapidity particles. The combined stored energy of this system is 13.8 GJ. This design is discussed in terms of powering and quench protection, conductor composition, mechanical properties of the cold masses and vacuum vessels, stray fields, and heat loads. In addition, alternative designs are discussed, including an ultrathin superconducting solenoid concept with comparatively low stored magnet energy. Like the ATLAS central solenoid, this solenoid provides a magnetic field to the tracker, and particles have to tunnel through the solenoid before reaching the calorimeters. An iron yoke returns the flux, thus providing bending power for muon tagging and giving complete magnetic shielding.

VIPER: an industrially scalable high-current high-temperature superconductor cable

Abstract: High-temperature superconductors (HTS) promise to revolutionize high-power applications like wind generators, DC power cables, particle accelerators, and fusion energy devices. A practical HTS cable must not degrade under severe mechanical, electrical, and thermal conditions; have simple, low-resistance, and manufacturable electrical joints; high thermal stability; and rapid detection of thermal runaway quench events. We have designed and experimentally qualified a vacuum pressure impregnated, insulated, partially transposed, extruded, and roll-formed (VIPER) cable that simultaneously satisfies all of these requirements for the first time. VIPER cable critical currents are stable over thousands of mechanical cycles at extreme electromechanical force levels, multiple cryogenic thermal cycles, and dozens of quench-like transient events. Electrical joints between VIPER cables are simple, robust, and demountable. Two independent, integrated fiber-optic quench detectors outperform standard quench detection approaches. VIPER cable represents a key milestone in next-step energy generation and transmission technologies and in the maturity of HTS as a technology.

Strategic RD Programme on Technologies for Future Experiments

Abstract: Instrumentation is a key ingredient for progress in experimental high energy physics. The Experimental Physics Department of CERN has defined a strategic R&D (Research and Development) programme on technologies for future experiments. Provided the required resources can be made available, it will start in 2020 and initially extend over five years. The selection of topics and the established work plans are the result of a transparent and open process, which lasted 14 months and involved several hundred of physicists and engineers at CERN and in the broader HEP community. This R&D programme is in the tradition of previous similar initiatives, the DRDC projects in the 1990’s and the White Paper R&D programme (2008-2011) that have been instrumental in providing the technologies which are presently in use at the LHC experiments or which will be deployed in the coming LHC upgrades (Phase-I and PhaseII). Examples of the achievements of the White Paper R&D programme are the validation of the CMOS 130 nm technology, the GEM single mask technique, radiation hard optical links, DC-DC converters and the CernVM file system. The results of this new R&D programme will be building blocks, demonstrators and prototypes, which will form the technological basis for possible new experiments and experiment upgrades beyond the LHC Phase-II upgrades scheduled for the long shutdown LS3. These include in particular detectors at CLIC, FCC-hh and FCC-ee but also further upgrades of the LHC experiments. The main challenges come on the hadron collider side from the very high luminosity operation, leading to extreme pile-up, track density, radiation loads and data throughput, but also from the need for unprecedented precision in vertexing and tracking, combined with very low material budgets and highly granular calorimetry on the lepton collider side. The new programme targets the primary challenges of the detectors complemented by equally demanding challenges in the domains of electronics, mechanics, cooling, magnets and software. A large part of the required R&D work will be carried out jointly with external groups from universities and research labs exploiting organically grown networks and relations, but also dynamic and efficient structures like the RD50 and RD51 collaborations. For many developments, close cooperation with industrial partners will be crucial.

Design of the Optional Forward Superconducting Dipole Magnet for the FCC-hh Detector

Abstract: A 4-T, 10-m free bore and 20-m long central solenoid is proposed as the main magnet in the baseline detector for the future circular collider (FCC) hadron–hadron collisions physics program. Besides the 4-T axial magnetic field around the interaction point in the center of the main solenoid, additionally, magnetic field is required in the forward directions. This provides sufficient bending power for particles traveling at small angles from the beam axis as well. Using forward solenoids is the baseline. Here, we present the option of using forward dipole magnets. A previously published design foresaw cone-shaped dipole magnets as well as force and torque balanced. This design, however, evolved to a more practical design, where the cryostat occupies the same space as in the baseline with forward solenoids, meaning that the vacuum vessel dimensions in solenoid and dipole designs are the same.

Development of light and highly radiation transparent cryostats for FCC detector magnets: first analyses of insulation materials

Abstract: For both versions of the Future Circular Collider, the electron-positron FCC ee+, requiring a 2 T/4 m bore solenoid for particles spectrometry, and the hadron-hadron FCC hh, CERN is developing an innovative design for the detector solenoids, to enable their positioning inside the calorimeters directly surrounding the inner tracker. For this to happen, the cryostat design has to be optimized to achieve minimum radiation length. The novel design consists of a sandwich of thin inner and outer metallic shells for vacuum tightness, supported by an insulating material with sufficient mechanical resistance paired with lowest thermal conductivity, like Cryogel, a flexible aerogel structure (density 0.16 g/cm 2 ), or glass spheres (e.g.Type K1 manufactured by 3M, with 65 μm diameter and density of 0.125 g/cm 3 ). These materials would allow constructing a 4 m bore, 6 m long cryostat with a 250 mm total thickness, a heat load less than 400 W on the cold mass and 10 kW on the thermal shield. In this paper, design options are discussed and methods for qualifying the materials presented.

Superconducting detector magnets for high energy physics

Abstract: Various superconducting detector solenoids for particle physics have been developed in the world. The key technology is the aluminum-stabilized superconductor for almost all the detector magnets in particle physics experiments. The coil fabrication technology is also important and it has advanced along with the conductor technology, such as the inner coil winding technique, indirect cooling, transparent vacuum vessel, quench protection scheme using pure aluminum strips and so on. The detector solenoids design study is in progress for future big projects in Japan and Europe, that is, ILC (International Linear Collider), FCC (Future Circular Collider) and CLIC (Compact LInear Collider), based on the technologies established over many years. The combination of good mechanical properties and keeping a high RRR is a key point for the development of Al-stabilized conductor. The present concern for the detector solenoid development is to have been nearly losing the key technologies and experiences. Nowadays, there are no industrial companies having the capacity to manufacture such aluminum stabilized superconductor. Complementary efforts are seriously required to re-realize and validate the performance required in the future projects in collaboration with worldwide institutes and industries. Some mid-scale physics experiments required detector solenoids wound with not aluminum stabilized conductor but conventional copper stabilized conductor. The specific requirement is to control the magnetic field distribution precisely, and the efforts to realize the requirement are on going with regard to the magnetic field design technology with high precision simulation, coil fabrication technology and so on.