Cable Magnetization Effects in the LHC Main Dipole Magnets

Bottura, L.; Schneider, Marcel; Walckiers, L.; Wolf, R.

doi:10.1007/978-1-4757-9047-4_54

Cited by 4 publications

(3 citation statements)

References 8 publications

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“…where b n is the normal and a n is the skew multipole coefficient of order n [38,39]. Both coefficients, normalized to the dipole field (B 1 ), are expressed in units (10 −4 ) at a reference radius (R ref ) of 21.55 mm, covering 55% of the aperture determined by the Layer 1 wire (table 2).…”

Section: Field Qualitymentioning

confidence: 99%

Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC^® wires

Wang

Abraimov

Arbelaez

et al. 2020

Supercond. Sci. Technol.

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Although the high-temperature superconducting (HTS) REBa 2 Cu 3 O x (REBCO, RE = rare earth elements) material has a strong potential to enable dipole magnetic fields above 20 T in future circular particle colliders, the magnet and conductor technology needs to be developed. As part of an ongoing development to address this need, here we report on our CORC ® canted cos θ magnet called C2 with a target dipole field of 3 T in a 65 mm aperture. The magnet was wound with 70 m of 3.8 mm diameter CORC ® wire on machined metal mandrels. The wire had 30 commercial REBCO tapes from SuperPower Inc., each 2 mm wide with a 30 µm thick substrate. The magnet generated a peak dipole field of 2.91 T at 6.290 kA, 4.2 K. The magnet could be consistently driven into the flux-flow regime with reproducible voltage rise at an engineering current density between 400 -550 A mm −2 , allowing reliable quench detection and magnet protection. The C2 magnet represents another successful step towards the development of high-field accelerator magnet and CORC ® conductor technologies. The test results highlighted two development needs: continue improving the performance and flexibility of CORC ® wires and develop the capability to identify locations of first onset of flux-flow voltage.

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Section: Field Qualitymentioning

confidence: 99%

Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC^® wires

Wang

Abraimov

Arbelaez

et al. 2020

Supercond. Sci. Technol.

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“…The data reduction followed the procedure described in [22]. First, the current was ramped up and held at 4 kA to measure the dipole field in the bore along the main axis of the coil.…”

Section: V-i V-imentioning

confidence: 99%

First demonstration of high current canted-cosine-theta coils with Bi-2212 Rutherford cables

Fajardo¹,

Shen²,

Wang³

et al. 2021

Supercond. Sci. Technol.

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Future high energy physics colliders could benefit from accelerator magnets based on high-temperature superconductors, which may reach magnetic fields of up to 45 T at 4.2 K, twice the field limit of the two Nb-based superconductors. Bi2Sr2CaCu2O8-x (Bi-2212) is the only high-T c cuprate material available as a twisted, multifilamentary and isotropic round wire. However, it has been hitherto unclear how an accelerator magnet can be fabricated from Bi-2212 round wires and whether high field quality can be achieved. This paper reports on the first demonstration of high current Bi-2212 coils using Rutherford cable based on a canted-cosine-theta (CCT) design and an overpressure processing heat treatment. Two Bi-2212 CCT coils, BIN5a and BIN5b, were made from a nine-strand Rutherford cable. Their electromagnetic design is identical, but they were fabricated differently: both coils underwent heat treatment in their aluminum–bronze mandrels, but unlike BIN5a that was impregnated with epoxy in its reaction mandrel, the conductor of BIN5b was transferred to a 3D printed Accura Bluestone mandrel after the heat treatment, a process attempted here for the first time, and was not impregnated. BIN5a reached a peak current of 4.1 kA with a self-field of 1.34 T in the bore. This corresponds to a wire engineering current density (J e) of 912 A mm−2, which is two times that of BIN2-IL, a previous Bi-2212 CCT coil fabricated at LBNL, which used a six-around-one cable processed with the conventional 1 bar pressure melt processing. On the other hand, BIN5b reached 3.1 kA. The coils exhibited no quench training. All the quenches were thermal runaways that occurred at the same location. In addition, we report on the field quality and ramp-dependent hysteresis measurements taken during the test of BIN5a at 4.2 K. Overall, our results demonstrate that the CCT technology is a route that should be further investigated for making high field, potentially quench training free dipole magnets with Bi-2212 cables.

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“…The measurement procedure consists of setting the magnetic field level B inside the reference dipole ([0.0, 0.2, 0.4, 0.6, 0.8, 1.0] T) and measuring it through the transducer for different angular rotating speeds ω ([1.000, 2.000, 3.000] rps). According to the classical procedure for rotating coil measurements [38], the magnetic flux is computed by integrating the coil voltage and adding the flux increments measured by the FDI triggered by the encoder pulses. In this test, only the main dipolar field component B 1 , obtained from the fundamental harmonic of flux, is considered, because the transducer includes only an absolute coil (uncompensated coil, i.e.…”

Section: Test Proceduresmentioning

confidence: 99%

A rotating coil transducer for magnetic field mapping

et al. 2015

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A rotating coil transducer for local measurements of magnetic field quality in magnets is proposed. The transducer is based on (i) reduced-dimension rotating coils, as required e.g. for space charge computations, (ii) accurate transport, for longitudinal displacements inside the magnet aperture, and (iii) components with magnetic compatibility for negligible interference of the measurand field. This allows magnetic measurement requirements arisen from recently developed compact accelerator systems (with curvature radii of less than 5 m) for biomedical applications and physics research to be satisfied. In the paper, after presenting requirements and conceptual design, the architecture of the transducer is illustrated. Then, the experimental validation by tests of magnetic compatibility and rotation uniformity is reported. Finally, experimental results of repeatability, accuracy, and resolution in comparison with a reference system are discussed.

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Cable Magnetization Effects in the LHC Main Dipole Magnets

Cited by 4 publications

References 8 publications

Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC^® wires

Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC^® wires

First demonstration of high current canted-cosine-theta coils with Bi-2212 Rutherford cables

A rotating coil transducer for magnetic field mapping

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Cable Magnetization Effects in the LHC Main Dipole Magnets

Cited by 4 publications

References 8 publications

Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC® wires

Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC® wires

First demonstration of high current canted-cosine-theta coils with Bi-2212 Rutherford cables

A rotating coil transducer for magnetic field mapping

Contact Info

Product

Resources

About

Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC^® wires

Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC^® wires