Mechanical Design, Assembly, and Test of LPF1: A 10.2 T Nb<sub>3</sub>Sn Common-Coil Dipole Magnet With Graded Coil Configuration

Zhang, Kai; Wang, Yingzhe; Cheng, Da; Kong, Ershuai; Peng, Quanling; Zhang, Zhan; Wei, Shaoqing; Yang, Xiudong; Xu, Qingjin

doi:10.1109/tasc.2018.2880172

Cited by 10 publications

(8 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…LPF1 was first fabricated to explore and address the manufacturing technology together with the performance characteristics of the high field dipole magnet with racetrack coils. The design of LPF1, described in detail in [11][12][13], was characterized by six double-pancake racetrack coils which were contained in a shell-based support structure using an external aluminum shell and pre-tensioned with bladders and keys [28]. Additionally, in the axial direction, two end plates and four aluminum tension rods were adopted for preloading.…”

Section: Fabrication Of Lpf1 and Lpf1-smentioning

confidence: 99%

“…To accomplish this target, a three-step R&D process has been proposed at IHEP [4][5][6][7][8][9]. For the first step, three subscale dipole magnets have already been designed, fabricated and tested with Nb 3 Sn and NbTi superconductors to investigate the fabrication process and characteristics of the common-coil dipole, and also to realize the 12 T magnetic field [10][11][12][13][14]. As an intermediate step, a 15-16 T dipole magnet could be fabricated with a combined configuration of Nb 3 Sn and HTS (high temperature superconducting) coils to test the stress management and quench protection methods of HTS coils.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Development of superconducting model dipole magnets beyond 12 T with a combined common-coil configuration

Wang

Shi

et al. 2023

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

The superconducting magnet group at IHEP (the Institute of High Energy Physics, Chinese Academy of Sciences, China) has been engaging in the R&D of high field accelerator magnets since 2014 for the pre-study of the next-generation high energy particle accelerators like CEPC-SPPC (Circular Electron Positron Collider-Super Proton Proton Collider), FCC (Future Circular Collider) and etc. A superconducting model dipole magnet named LPF1 was firstly fabricated with NbTi and Nb3Sn combined common-coil configuration in 2017 and tested in 2018, a main field of 10.23 T was reached within two 10-mm apertures. The magnet was reassembled with higher pre-stress in 2019 to investigate the influence of pre-stress loading level on the performance of common-coil dipole magnets. The main field of this upgraded magnet named LPF1-S was increased to 10.71 T within two 12-mm apertures. By improving the key process technologies in Rutherford cable fabrication, coil winding, Nb3Sn & NbTi splices soldering and coil impregnation, the recently fabricated model dipole magnet named LPF1-U got a 12.47-T main field in two 14-mm apertures in 2021. To fully take advantage of Nb3Sn and NbTi superconductors in different field regions, LPF1-U was still designed and developed with a combined coil configuration with Nb3Sn for the inner two coils and NbTi for the outer four coils. Besides, graded coil topology and different coil LSS (length of straight section) settings were adopted in the optimization of LPF1-U layouts. Bladder and key technology was used for the support structure and fiber optic sensors based on the FBG (Fiber Bragg Grating) were utilized to monitor the stress distribution and variation in the structures and coils through the whole process from magnet assembly to cool-down and excitation. During the performance test, a relatively large number of trainings were carried out and LPF1-U became more stable after thermal cycle. A peak field of 12.7 T in coils (12.47 T main field in apertures) corresponds to the operating current of 6865 A and the load line ratio of 90 % was finally attained. It is worth mentioning that LPF1-U is the first hybrid - Nb3Sn, NbTi- common coil dipole magnet which has achieved a main field of more than 12 T in two apertures. The design, fabrication and performance analysis of LPF series dipole magnets are presented in this paper.

show abstract

Section: Fabrication Of Lpf1 and Lpf1-smentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Development of superconducting model dipole magnets beyond 12 T with a combined common-coil configuration

Wang

Shi

et al. 2023

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The magnet is composed of two Nb 3 Sn coils and four NbTi coils. The detailed mechanical structure and design of the magnet are described in [10], [11]. The stress simulations of the magnet include three load steps: assembly, cool down, and magnet excitation.…”

Section: The Stress Analysis Of the Sc Magnet And The Strandmentioning

confidence: 99%

“…Secondly, based on the actual SC strand structure inside the SC coil, the homogenization finite element model of the strand is built, and effective material coefficients are calculated. Finally, a stress analysis of the SC magnet named LPF1 developed at IHEP [10], [11] is performed, which simulates three load steps: magnet assembly, cool down and excitation with effective material coefficients and isotropic material coefficients. The stress in the filament and strand is recovered and discussed based on the simulation results for the magnet during excitation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Study on Internal Strain Distribution of the High-Field Nb₃Sn Superconducting Accelerator Magnets With Homogenization Theory

Zhang

2022

IEEE Access

Self Cite

View full text Add to dashboard Cite

To fabricate 10-16 Tesla high-field accelerator magnets, the high-Jc Nb 3 Sn superconductor is one of the most practical choices. However, it is a brittle material and is strain-sensitive. To reduce the potential Jc degradation of the conductor, it is crucial to accurately evaluate the stress of the coils owing to the large Lorentz force during magnet excitation. In the traditional stress analysis of magnets, the coils are usually regarded as homogenized structures using isotropic material coefficients; however, most superconducting (SC) coils have hierarchical and complicated structures. To obtain a more accurate estimation, it is necessary to consider the detailed internal structure of the coils during stress analysis. In this study, the homogenization method was applied to multi-scale stress analysis of a high-field accelerator SC magnet. The effective material coefficients of Nb 3 Sn coils were calculated using this method. Stress analysis of the magnet was performed using the effective material coefficients and isotropic material coefficients for comparison. Compared with the result obtained using isotropic material coefficients, the Von-Mises stress of the coil using effective material coefficients is larger at different load steps. The stress level of most Nb 3 Sn filaments in the strand was higher than that of the coil. The maximum stress of the Nb 3 Sn filaments appeared in the strand contact regions. In addition, there was a significant difference in the average stress of all materials in the strand. These findings will help develop more accurate analysis and simulation models for high-field SC magnets.INDEX TERMS Homogenization method, Nb 3 Sn, stress analysis, superconducting magnet.

show abstract

Strain Measurement Method Based on External Symmetrical Compensation Bridge Composed of Strain Gauges with Four-Wire Configuration for a Large-Scale NbTi Superconducting Dipole Magnet Detector

Zhang,

Xin,

Gao

et al. 2023

J Low Temp Phys

View full text Add to dashboard Cite

In this study, we present a strain measurement method based on an external symmetrical compensation bridge (ESCB) composed of strain gauges with a four-wire con guration. Unlike the traditional strain measurement methods, this method includes two features: rst, utilising the four-wire con guration to eliminate measurement errors that occur due to large space-varying thermal and eld imbalances of long signal wires during operation, and second, utilising two independent quarter-active sub-bridges with a four-wire con guration composed of ESCB to eliminate the errors that occur due to the large time-varying cryogenic temperature and magnetic eld. This method was used on a large-scale NbTi superconducting dipole magnet detector during the cooling, excitation, and quench tests. The strains measured using the ESCB were compared with those measured using a traditional half-active compensation bridge. The results indicated that the new method can accurately detect the strain features of a large-scale superconducting magnet. In addition, using the proposed method, spectrum analysis of strain measurements was implemented during excitation, quench onset, and post-quench. A larger amplitude at a higher frequency was clearly observed at the onset of a quench than that observed during excitation and post-quench. Thus, the dynamic strain characteristics of a superconducting magnet structure could be a candidate for predicting the quench.

show abstract

Mechanical Design, Assembly, and Test of LPF1: A 10.2 T Nb₃Sn Common-Coil Dipole Magnet With Graded Coil Configuration

Cited by 10 publications

References 31 publications

Development of superconducting model dipole magnets beyond 12 T with a combined common-coil configuration

Development of superconducting model dipole magnets beyond 12 T with a combined common-coil configuration

Study on Internal Strain Distribution of the High-Field Nb₃Sn Superconducting Accelerator Magnets With Homogenization Theory

Strain Measurement Method Based on External Symmetrical Compensation Bridge Composed of Strain Gauges with Four-Wire Configuration for a Large-Scale NbTi Superconducting Dipole Magnet Detector

Contact Info

Product

Resources

About

Mechanical Design, Assembly, and Test of LPF1: A 10.2 T Nb3Sn Common-Coil Dipole Magnet With Graded Coil Configuration

Cited by 10 publications

References 31 publications

Development of superconducting model dipole magnets beyond 12 T with a combined common-coil configuration

Development of superconducting model dipole magnets beyond 12 T with a combined common-coil configuration

Study on Internal Strain Distribution of the High-Field Nb₃Sn Superconducting Accelerator Magnets With Homogenization Theory

Strain Measurement Method Based on External Symmetrical Compensation Bridge Composed of Strain Gauges with Four-Wire Configuration for a Large-Scale NbTi Superconducting Dipole Magnet Detector

Contact Info

Product

Resources

About

Mechanical Design, Assembly, and Test of LPF1: A 10.2 T Nb₃Sn Common-Coil Dipole Magnet With Graded Coil Configuration