Design, fabrication and testing of a dipole magnet made with 2G HTS wire

REBa 2 Cu 3 O x (REBCO, RE = rare earth elements) coated conductors can carry high current in high background fields, in principle enabling dipole magnetic fields beyond 20 T. Although model accelerator magnets wound with single REBCO tapes have been successfully demonstrated, magnet technology based on high-current REBCO cables for high-field accelerator magnet applications has yet to be established. We developed a two-layer canted cos θ dipole magnet with an aperture of 70 mm using 30 m long commercial Conductor on Round Core (CORC R) wires. The 3.1 mm diameter CORC R wire contained 16 commercial REBCO tapes with a 30-µm thick substrate. The magnet was tested at 77 and 4.2 K. It generated a peak dipole field of 1.2 T with 4.8 kA at 4.2 K with neither thermal runaway nor training. Reasonable geometric field quality and strong magnetization-current effects with multipole decay were observed. Our work demonstrated a feasible high-temperature superconducting magnet technology as a first step toward a new accelerator magnet paradigm that will enable high-field inserts for next-generation circular colliders and stand-alone magnets that can operate over a wide temperature range for a broad range of applications.

Section: Introductionmentioning

confidence: 99%

A 1.2 T canted cosθ dipole magnet using high-temperature superconducting CORC^® wires

Wang

Dietderich

DiMarco

et al. 2019

“…Compared to the significant progress in high-field solenoid magnets made with REBCO tapes [4][5][6][7][8][9], the development of REBCO high-field accelerator magnets is less advanced, limited by the use of single tapes [10][11][12][13][14]. Two technical issues can partially explain this.…”

Section: Introductionmentioning

confidence: 99%

A viable dipole magnet concept with REBCO CORC^®wires and further development needs for high-field magnet applications

Wang

Caspi

Dietderich

et al. 2018

REBCO coated conductors maintain high engineering current density above 16 T at 4.2 K. That fact will significantly impact markets of various magnet applications including high-field magnets for high-energy physics and fusion reactors. One of the main challenges for the high-field accelerator magnet is the use of multitape REBCO cables with high engineering current density in magnet development. Several approaches developing high-field accelerator magnets using REBCO cables are demonstrated. In this paper, we introduce an alternative concept based on the canted cos θ (CCT) magnet design using Conductor on Round Core (CORC R) wires that are wound from multiple REBCO tapes with a Cu core. We report the development and test of double-layer three-turn CCT dipole magnets using CORC R wires at 77 K and 4.2 K. The scalability of the CCT design allowed us to effectively develop and demonstrate important magnet technology features such as coil design, winding, joints and testing with minimum conductor lengths. The test results showed that the CCT dipole magnet using CORC R wires was a viable option in developing REBCO accelerator magnet. One of the critical development needs is to increase the engineering current density of the 3.7 mm diameter CORC R wire to 540 A mm −2 at 21 T, 4.2 K and to reduce the bending radius to 15 mm. This would enable a compact REBCO dipole insert magnet to generate a 5 T field in a background field of 16 T at 4.2 K.

“…In order to further increase the competitiveness of SuperOx wire in various applications in magnetic field [4][5][6][7][8][9][10][11][12], we have initiated an industrial R&D programme aimed at improving the wire's superconducting performance in external magnetic field by means of introducing perovskite artificial pinning centres (APC) into the HTS layer.…”

Section: Introductionmentioning

confidence: 99%

Introduction of BaSnO₃and BaZrO₃artificial pinning centres into 2G HTS wires based on PLD-GdBCO films. Phase I of the industrial R&D programme at SuperOx

Chepikov

Mineev²,

Degtyarenko³

et al. 2017

An industrial R&D programme is ongoing at SuperOx, aimed at improving 2G HTS wire performance in magnetic field. We introduce perovskite artificial pinning centres (APC) into the HTS layer matrix. In contrast to most studies described in the literature, we use the high rate production processing parameters and PLD equipment at SuperOx. This paper reports the results of Phase I of this programme. We fabricated 2G HTS wires by pulsed laser deposition of GdBCO films doped with 6%, 12% and 18% (molar) of BaSnO3 and 6% (molar) of BaZrO3, and compared their performance with an undoped reference sample. The depositions were carried out at production growth rates of 375, 560 and 750 nm min−1 by varying laser pulse frequency. BaZrO3 and BaSnO3 formed columnar semi-coherent nanoinclusions in the GdBCO film matrix. The average transverse size of the nanocolumns was about 5 nm, and their volume density correlated with the dopant concentration. All doped samples exhibited much lower angular anisotropy of in-field critical current and higher lift-factors than the undoped sample. Samples containing 6% BaSnO3 and deposited at the lower growth rates, had higher Ic than the undoped sample in the entire temperature range, in a wide range of magnetic field (B//c). The sample containing 6% BaZrO3 had higher Ic than the undoped sample at 20 and 4.2 K. These results are an encouraging start of our programme, as they show a positive impact of APC introduced into 2G HTS wires fabricated at production throughput. Phase II work will be focussed on maximising the improvements in specific temperature and field conditions, as well as on the verification of reproducibility of the improvements in production wires.