Design and Engineering of an HTS Dipole in the FRIB Fragment Separator

Song, Honghai; Burkhardt, E.E.; Borden, T.; Chouhan, S.; Cole, D.; Georgobiani, D.; Hausmann, M.; Patil, M.; Portillo, M.; Ronningen, R. M.; Swanson, R.; Xu, Yi; Zeller, A.

doi:10.1109/tasc.2014.2374602

Cited by 15 publications

(5 citation statements)

References 11 publications

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“…Therefore, it can be deduced that the disturbance energy of the coil became lower and that the structure of the coil may become unstable even at very small crisis. In addition, the method is also suitable for the quench detection in the case of a distributed heat load, such as particle shower or bremsstrahlung radiation in an accelerator environment, or neutron energy deposition in a nuclear power plant environment, due to the local defects inducing a quench onset [55,56].…”

Section: Resultsmentioning

confidence: 99%

“…However, a quench in a superconducting magnet is essentially the accumulation of continuous mechanical or vibration events, and thus a series of disturbed strain signals may be generated by the unexpected sudden thermomechanical events during a quench. Though in case of a distributed heat load, such as particle shower or bremsstrahlung radiation in an accelerator environment, or neutron energy deposition in a nuclear power plant environment, external disturbance is different from local thermal (or mechanical) disturbance, because of the local defects, a quench still starts in the local weak area (the location of the defect), and then normal zone propagates to other parts of the superconductor conductor [55,56]. Therefore, it is also suitable for the quench detection in the case of a distributed heat load.…”

Section: Introductionmentioning

confidence: 99%

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A dynamic strain-based quench-detection method in an LTS sextupole magnet during excitation and quench

Gao

Guan

Xin

2020

Supercond. Sci. Technol.

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The dynamic strain characteristics and responses of a low-temperature superconducting (LTS) magnet during excitation and a quench are investigated in the present work. For the strain measurements, strain gauges in the form of a half-bridge circuit comprising cryogenic strain gauges and their dummy resistances are embedded directly within the superconducting magnet structure. A wireless high-speed data acquisition system with a resolution of 1 ms is also used to obtain the strain history of the LTS magnet during operation. The dynamic strain induced by thermal or mechanical disturbances is detected promptly and compared with the transport current and temperature signals recorded during a quench. This indicates that the dynamic strain measured in the LTS magnet can capture a quench feature in a timely manner. For a better understanding of the dynamic strain histories in the magnet, the dynamic strain signals are subjected to spectral analysis during the excitation and pre- and post-quench processes. It is shown originally that several spectral peaks on strain measured are always observed at the onset of a quench. Thus, the dynamic strain characteristics and responses provide a evaluation means of superconducting magnet.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A dynamic strain-based quench-detection method in an LTS sextupole magnet during excitation and quench

Gao

Guan

Xin

2020

Supercond. Sci. Technol.

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“…As a result, the cost contingency and schedule contingency must be higher. For this reason FRIB decided not to build a HTS fragment separator dipole [22].…”

Section: Discussionmentioning

confidence: 99%

A Cyclotron Magnet Case Study: Would Replacing the LTS Coils With HTS Coils Make Sense?

Green

Chouhan

2016

IEEE Trans. Appl. Supercond.

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The cyclotron gas-stopper magnet (CGSM) at Michigan State University (MSU) was used as model for a study for whether HTS conductor is feasible for use in cyclotrons. The outside diameter of the CGSM split warm iron magnet yoke is 4 m, with a pole radius of 1.1 m. The desired field shape is obtained by shaping the iron pole profile. Each superconducting coil is in a separate cryostat. The two coils are connected in series through the warm electrical connection. Each coil is wound and potted within an 80 mm × 80 mm cross section and mounted within a 304 stainless steel helium vessel that is designed to carry magnetic forces to the magnet cold mass supports without excessive deflection. The iron is split, so that the cyclotron chamber and RF extraction system can be mounted between the two poles. This magnet has been successfully cooled down and tested at MSU to its 180-A operating current. One can ask the following question, "If one built a cyclotron magnet the size of the MSU cyclotron gas-stopper magnet, would replacing the existing LTS coils with HTS coils using a standard second generation HTS tape make technical sense or economic sense?" The report will explore the technical and economic issues of replacing an existing LTS coil with an HTS coil of the same size and shape, using 2G YBCO tape conductor commercially available in 2015 in place of the Nb-Ti used in the magnet.

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“…η is a practical ratio. For example, in an accelerator system, the variation in magnetic field is required to be less than 0.4% [11]. Therefore, the ratio η is set to be 99.6%, 98% and 95% for comparison and analysis in this study.…”

Section: The Charging Time Of Nei Coilsmentioning

confidence: 99%

“…In most of the practical and large superconducting magnet systems, the HTS magnet often requires to be charged to a desired magnetic field within a specific time, such as in the accelerator system, MRI magnet and DC induction heater device [11][12][13][14]. However, for NEI coils, the total charging time required may be much longer than that of its conventional insulated counterpart, due to the intrinsic charging delay [10,15,16].…”

Section: Introductionmentioning

confidence: 99%

Influence of turn-to-turn resistivity and coil geometrical size on charging characteristics of no-electrical-insulation REBCO pancake coils

Wang

Song

2016

Supercond. Sci. Technol.

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High temperature superconductor (HTS) no-electrical-insulation (NEI) coils demonstrate great advantages in thermal stability and self-protection features. However, an intrinsic delay is observed in the charging process and as a result there maybe a possible settle-out problem. It becomes more critical for large HTS coils with more turns, such as the magnets for the accelerator system and DC induction heater applications. This paper presents detailed studies on the charging characteristics of NEI coils. Firstly, two different no-electrical-insulation coils are wound: the first is directly wound using only REBCO tapes with brass lamination, which is called a no-insulation (NI) coil. The other one is co-wound with stainless steel (SS) strips and REBCO tapes whose copper stabilizer is electroplated, which is called a metallic insulation (MI) coil. Fast discharging tests are performed on the two coils and their equivalent turn-to-turn resistivity is calculated. A similar discharging delay is observed on both coils, but the turn-to-turn resistivity of the SS co-wound coil is much higher than that of the first coil. Then the resistivity data is directly applied to an equivalent circuit network model which is developed to predict the charging behaviours. The model calculates coil voltage, currents along the azimuthal and radial directions, as well as the induced magnetic field. A practical charging time is defined to characterize the field ramping process considering the charging delay between field ramping and current charging. The charging behaviours are extensively analyzed and compared in terms of three primary factors: equivalent turn-to-turn resistivity, coil size and ramping rate. The results show that the charging time increases dramatically with the coil size and may be too long to be practical for large-scale applications using HTS coils with low turn-to-turn resistivity. Increasing the turn-to-turn resistivity enables one to accelerate the charging process effectively. Therefore, the SS co-wound coil with higher turn-to-turn resistivity shows a much shorter charging time, which indicates that it may be more suitable for large-scale HTS magnets.

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Design and Engineering of an HTS Dipole in the FRIB Fragment Separator

Cited by 15 publications

References 11 publications

A dynamic strain-based quench-detection method in an LTS sextupole magnet during excitation and quench

A dynamic strain-based quench-detection method in an LTS sextupole magnet during excitation and quench

A Cyclotron Magnet Case Study: Would Replacing the LTS Coils With HTS Coils Make Sense?

Influence of turn-to-turn resistivity and coil geometrical size on charging characteristics of no-electrical-insulation REBCO pancake coils

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