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H. H. J. ten Kate

Publications and source records attributed to H. H. J. ten Kate.

8 recordsLinked to original sources
arXiv2022

Training performance of Nb3Sn Rutherford cables in a channel with a wide range of impregnation materials

Training of accelerator magnets is a costly and time consuming process. The number of training quenches must therefore be reduced to a minimum. We investigate training of impregnated Nb3Sn Rutherford cable in a small-scale experiment. The test involves a Rutherford cable impregnated in a meandering channel simulating the environment of a canted-cosine-theta (CCT) coil. The sample is powered using a transformer and the Lorentz force is generated by an externally applied magnetic field. The low material and helium consumption enable the test of a larger number of samples. In this article, we present training of samples impregnated with alumina-filled epoxy resins, a modified resin with paraffin-like mechanical properties, and a new tough resin in development at ETH Zürich. These new data are compared with previous results published earlier. Compared to samples with unfilled epoxy resin, those with alumina-filled epoxy show favorable training properties with higher initial quench currents and fewer training quenches before reaching 80% of the critical current.

physics.acc-ph↗
arXiv2015

Superconducting Magnet with the Reduced Barrel Yoke for the Hadron Future Circular Collider

The conceptual design study of a hadron Future Circular Collider (FCC-hh) with a center-of-mass energy of the order of 100 TeV in a new tunnel of 80-100 km circumference assumes the determination of the basic requirements for its detectors. A superconducting solenoid magnet of 12 m diameter inner bore with the central magnetic flux density of 6 T is proposed for a FCC-hh experimental setup. The coil of 24.518 m long has seven 3.5 m long modules included into one cryostat. The steel yoke with a mass of 21 kt consists of two barrel layers of 0.5 m radial thickness, and 0.7 m thick nose disk, four 0.6 m thick end-cap disks, and three 0.8 m thick muon toroid disks each side. The outer diameter of the yoke is 17.7 m; the length without the forward muon toroids is 33 m. The air gaps between the end-cap disks provide the installation of the muon chambers up to the pseudorapidity of \pm 3.5. The conventional forward muon spectrometer provides the measuring of the muon momenta in the pseudorapidity region from \pm 2.7 to \pm 4.6. The magnet modeled with Cobham's program TOSCA. The total Ampere-turns in the superconducting solenoid coil are 127.25 MA-turns. The stored energy is 43.3 GJ. The axial force onto each end-cap is 480 MN. The stray field at the radius of 50 m off the coil axis is 14.1 mT and 5.4 mT at the radius of 100 m. All other parameters presented and discussed.

physics.ins-det↗
arXiv2014

The influence of the Al stabilizer layer thickness on the normal zone propagation velocity in high current superconductors

The stability of high-current superconductors is challenging in the design of superconducting magnets. When the stability requirements are fulfilled, the protection against a quench must still be considered. A main factor in the design of quench protection systems is the resistance growth rate in the magnet following a quench. The usual method for determining the resistance growth in impregnated coils is to calculate the longitudinal velocity with which the normal zone propagates in the conductor along the coil windings. Here, we present a 2D numerical model for predicting the normal zone propagation velocity in Al stabilized Rutherford NbTi cables with large cross section. By solving two coupled differential equations under adiabatic conditions, the model takes into account the thermal diffusion and the current redistribution process following a quench. Both the temperature and magnetic field dependencies of the superconductor and the metal cladding materials properties are included. Unlike common normal zone propagation analyses, we study the influence of the thickness of the cladding on the propagation velocity for varying operating current and magnetic field. To assist in the comprehension of the numerical results, we also introduce an analytical formula for the longitudinal normal zone propagation. The analysis distinguishes between low-current and high-current regimes of normal zone propagation, depending on the ratio between the characteristic times of thermal and magnetic diffusion. We show that above a certain thickness, the cladding acts as a heat sink with a limited contribution to the acceleration of the propagation velocity with respect to the cladding geometry. Both numerical and analytical results show good agreement with experimental data.

physics.acc-ph↗
arXiv2013

The Superconducting Toroid for the New International AXion Observatory (IAXO)

IAXO, the new International AXion Observatory, will feature the most ambitious detector for solar axions to date. Axions are hypothetical particles which were postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP (Charge conjugation and Parity) problem. This detector aims at achieving a sensitivity to the coupling between axions and photons of one order of magnitude beyond the limits of the current detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions to detectable X-ray photons. Inspired by the ATLAS barrel and end-cap toroids, a large superconducting toroid is being designed. The toroid comprises eight, one meter wide and twenty one meters long racetrack coils. The assembled toroid is sized 5.2 m in diameter and 25 m in length and its mass is about 250 tons. The useful field in the bores is 2.5 T while the peak magnetic field in the windings is 5.4 T. At the operational current of 12 kA the stored energy is 500 MJ. The racetrack type of coils are wound with a reinforced Aluminum stabilized NbTi/Cu cable and are conduction cooled. The coils optimization is shortly described as well as new concepts for cryostat, cold mass, supporting structure and the sun tracking system. Materials selection and sizing, conductor, thermal loads, the cryogenics system and the electrical system are described. Lastly, quench simulations are reported to demonstrate the system's safe quench protection scheme.

physics.ins-det↗
arXiv2013

New Superconducting Toroidal Magnet System for IAXO, the International AXion Observatory

Axions are hypothetical particles that were postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP (Charge conjugation and Parity) problem. The new International AXion Observatory (IAXO) will incorporate the most promising solar axions detector to date, which is designed to enhance the sensitivity to the axion-photon coupling by one order of magnitude beyond the limits of the current state-of-the-art detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions into X-ray photons. Inspired by the successful realization of the ATLAS barrel and end-cap toroids, a very large superconducting toroid is currently designed at CERN to provide the required magnetic field. This toroid will comprise eight, one meter wide and twenty one meter long, racetrack coils. The system is sized 5.2 m in diameter and 25 m in length. Its peak magnetic field is 5.4 T with a stored energy of 500 MJ. The magnetic field optimization process to arrive at maximum detector yield is described. In addition, materials selection and their structure and sizing has been determined by force and stress calculations. Thermal loads are estimated to size the necessary cryogenic power and the concept of a forced flow supercritical helium based cryogenic system is given. A quench simulation confirmed the quench protection scheme.

physics.ins-det↗
arXiv2013

IAXO - The International Axion Observatory

The International Axion Observatory (IAXO) is a next generation axion helioscope aiming at a sensitivity to the axion-photon coupling of a few 10^{-12} GeV^{-1}, i.e. 1-1.5 orders of magnitude beyond sensitivities achieved by the currently most sensitive axion helioscope, the CERN Axion Solar Telescope (CAST). Crucial factors in improving the sensitivity for IAXO are the increase of the magnetic field volume together with the extensive use of x-ray focusing optics and low background detectors, innovations already successfully tested at CAST. Electron-coupled axions invoked to explain the white dwarf cooling, relic axions, and a large variety of more generic axion-like particles (ALPs) along with other novel excitations at the low-energy frontier of elementary particle physics could provide additional physics motivation for IAXO.

physics.ins-det↗
arXiv2012

Conceptual Design of a New Large Superconducting Toroid for IAXO, the New International AXion Observatory

The International AXion Observatory (IAXO) will incorporate a new generation detector for axions, a hypothetical particle, which was postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP problem. The new IAXO experiment is aiming at achieving a sensitivity to the coupling between axions and photons of one order of magnitude beyond the limits of the current state-of-the-art detector, represented by the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions into x-ray photons. Utilizing the designs of the ATLAS barrel and end-cap toroids, a large superconducting toroidal magnet is currently being designed at CERN to provide the required magnetic field. The new toroid will be built up from eight, one meter wide and 20 m long, racetrack coils. The toroid is sized about 4 m in diameter and 22 m in length. It is designed to realize a peak magnetic field of 5.4 T with a stored energy of 500 MJ. The magnetic field optimization process to arrive at maximum detector yield is described. In addition, force and stress calculations are performed to select materials and determine their structure and sizing. Conductor dimensionality, quench protection and the cryogenic design are dealt with as well.

physics.ins-det↗